This is a step-by-step guide on how to set up a nice graphical boot screen, similar to Mac OSX bootcamp, using a package called burg-manager (many thanks to Tracerneo for pointing this out in the thread).

Here's my own boot screen (click image for higher-res), just to give you an idea of what to expect. You can choose from a variety of themes, and you'll be happy to know that you can swap between themes at boot time, rather than via configuration files :)

There are five steps in this guide:

1. Configure grub2 via startupmanager
2. Install BUC (burg-manager depends on this package)
3. Install burg-manager
4. Use it to install burg as your default bootloader
5. Tweak the configuration files for 100% shininess :)

There's  also instructions on how to uninstall, if you need to, at the end of this tutorial.

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Step 1. Configure grub2 via startupmanager.

If you feel your boot sequence, as far as grub2 is concerned, is actually working fine, then skip this step. I had to tweak things a bit because I was getting this problem (which is one of the known problems we're warned about at the linux mint welcome screen). Incidentally, I only get this after I install my nvidia drivers, so you may not have gotten this problem at all, or may have had other problems. Either way, follow the instructions on that page, and play around with startupmanager until you're happy with your grub2 settings. Don't worry about background images at this point, as these won't be used by burg (you can add your own background picture using custom burg themes, which I'll mention later on).

As I wanted a fully graphical boot sequence, I chose the following settings, as they appear in the picture to the right (click for higher-res image), i.e. a boot splash (the 'Linux Mint - from freedom came elegance' graphical logo), suppressed verbose output, and a decent resolution.

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Step 2. Install 'Basta-Un-Click' (BUC).

We're now pretty much following the flow of the original article for installing burg-manager. You can either install BUC by downloading the deb package from this page and installing it using gdebi-gtk, or by using the repository method (the link has been 'google-translated' from italian for your convenience :) ). I chose the repository method, since there might be updates at some point I might benefit (or suffer) from. Ignore the "Vai alla cartella" notice you get btw, it's just a 'do you want to read the README file' thing. Click on it then, close it and proceed.

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Step 3. Install burg-manager

Again, follow the instructions in the sourceslist.eu website to install burg-manager either as a .deb file, or using a repository. I chose the repository. During installation you will be asked about grub2 settings, just choose the default settings everywhere (i.e. press enter)

(Note: One of the settings is which harddisk the bootloader will be written to. I'm assuming this will find the right one from grub, but it's worth keeping an eye for it. If it's wrong, use space to 'tick' the right one, before pressing enter. I only have one harddisk so there wasn't a choice issue for me here, but I thought I'd mention this just in case.)

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Step 4. Install burg as your bootloader

Burg-manager should now be on your MintMenu. Find it under 'System Tools -> Burg-manager' (or just run burg-manager from a console). Don't be alarmed if it's taking a while to show up; it needs to 'call home' first to do its business, which sometimes takes a while. In the opening screen click on burg-install. Make sure you choose the right hard-disk! (I only have the one so it wasn't an issue for me).

Apparently the developers predict that kernel/grub updates will probably mess things up. Whenever your update manager downloads a kernel update (you'll know because it will ask you to restart), come here and click on Restore Burg into MBR to reactivate the shiny graphical booting :)

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Step 5. Adjust settings and tweak the configuration files

First, click on the 'Themes Installer' tab and install any themes you like by double-clicking on them.

Then click on the 'Parameters' tab. If you're unlucky like I was, the 'Set Screen Resolution' menu (under the 'Basic Parameters' tab) will not have a suitable resolution for you to choose from. Don't worry about that, we'll tweak the configuration file manually in a minute. Set the timeout you want and click apply. You might also want to execute the 'Remove previous kernel versions' option, otherwise you may end up with multiple linux mint icons on your boot menu.

I'm guessing that when there's a kernel update, you'd also need to come here and execute this again, (as well as restoring burg to the MBR, as mentioned above), since kernel updates usually add more boot options to your list.

Now comes the tweaking part. Go to the 'Advanced Parameters' tab, and click the 'Open file' button on the top, to edit the /etc/default/burg file as root. If you want you can edit this without using burg-manager, but you'd need to run 'sudo update-burg' after you save it, to apply the changes -- burg-manager does this automatically for you as soon as you close the text editor it opened up for you (you still need to save the changes you made to the configuration file by manually clicking 'save' though)

Lines beginning with '#' are comments. Other lines represent commands. First thing you may note is that a lot of the comments talk about 'uncommenting the line below it.' However, if you clicked on the buttons in the basic parameters previously, it may have moved some of these commands at the end of the file, away from their comments. Don't worry about that. There are two important lines we need to change.

The first is this line:

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
# In the boot menu, use hotkey 'r' to popup a resolution selection menu.
GRUB_GFXMODE=default

and change it to

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
# In the boot menu, use hotkey 'r' to popup a resolution selection menu.
GRUB_GFXMODE=1024x768

This determines the resolution of the initial boot screen you see. It's not that crucial, as I think you can choose a different resolution at boot time by pressing 'r'. The important thing is that it's not a resolution that will not be supported by your monitor in basic (i.e. not hardware accelerated) mode.

The second step is adding this line at the end of the file:

GRUB_GFXPAYLOAD_LINUX=1024x768

This tells burg to continue at a resolution of 1024x768, which is necessary to get our nice little 'Linux Mint: from freedom came elegance' logo properly. If you don't add this, expect the non-graphical version.

Save the file and close it.

Note you don't then have to press 'Apply' in the 'Parameters' tab again, the configuration is now usable. In fact, pressing 'Apply' will overwrite any changes you've made in the file with settings that are present in the 'Parameters' form. (Thanks to goly for pointing this out)

If you now go back to the main 'Burg-Installer' screen, you can press on the 'burg-emu' key to see how your boot screen will look like. You can try out new themes by pressing 'T' (you can also do this at boot time).

Note that 'r' doesn't work in emulation mode, but at boot time, pressing 'r' will enable you to swap between available resolutions. You can press 'h' or F1 for some more commands.

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Uninstalling burg and reinstating grub2

Burg-manager has a tab called 'Remove Burg'. I tried this, but for some reason it did not revert to my earlier grub settings very well. Instead it gave me a white-on-black monochrome textbox with no background image, i.e. the most basic grub menu possible. If you get the same problem, you can fix it by manually running

sudo grub-install /dev/XXX

at a terminal, substituting XXX for the harddrive you boot from (mine was sda, which is the only harddisk I have). This brought me back to my good old hi-res grub2 boot screen with the linuxmint.png background image.

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That's it!  Have fun! If you want to hack around with the themes and mess around with the backgrounds or icons the themes use, look in /boot/burg/themes. The configuration files aren't too hard to follow.

PS. As an afterthought, if your motivation in wanting a fully graphical bootloader was to get as 'Mac OSX' like as possible, then you might also want to check out macbuntu. Though personally, I think the standard Linux Mint 10 desktop is 10 times more gorgeous, elegant, and functional than any of its 'competitors' :)