If you've installed apps into XFCE (that don't show up in the menu) and know what a pain in the butt it is (for me at least) to manually edit the menu OR you want a quick and dirty way to launch apps from the panel without loading it up with icons hence, reducing the size of your task list area OR you don't want to waste precious system resouces with a dock bar... are ya gettin' it yet? This is THE end all way to launch your favorite apps in XFCE:

The answer is to put the Application Finder on the panel, load it up with your most frequently used apps and, then turn it into a button to make a drop down menu list. Here's how you do it:

1. Right click on XFCE panel and select Add New Items.
2. Select 1st choice "Launcher" and click "Add", keep the dialog box open and drag it to the right side of your display (DO NOT click OK, just yet).
3. Then from the Main Menu, select Accessories > Application Finder and drag this dialog box over to the left part of your display (the launcher box should overlap).
4. In the Application Finder search box, type in the letters "app" and the Application Finder app should appear second in the list.
5. With your mouse, highlight Application Finder in the list and with  your mouse drag it into the open box in the Launcher dialog box you should still have open and place it underneath "New Item".
6. Then, go up to New Item, highlight it and then click the RED "-" sign to remove it.
7. Now, you are going to go back to the application finder dialog box and find each of your favorite apps and drag them over, one by one into the new Laucher box. I have Firefox, Transmission, Skype, FreeC++, Audacious, Chromium, Pidgin, Openoffice Writer, Synaptic, VLC, Ubuntu Tweak, Catfish and Terminal in mine.
8. Once you've loaded up your launcher click OK (you can do just a few apps now to try this procedure out, and add more later if you wish - it's very simple once you get the hang of it).
9. Now, this new panel item should appear on the left part of your panel next to the notifcation area (I prefr it to be on the left, so right click on it and select "Move" then drag it over to the left side of the panel nect to the "Places" icon.
10. Now the FINAL step... by default there should be a little arrow next to the magnifying glass icon and if you click on it your newly created snappy launcher with drop down with all your menu item. Personally, I don't like the arrow and I rather click on the icon itself to make the list drop down. So do this>>>
11. Highlight your icon on the panel, right click and select "Properties". THEN in the dialog box, look ON TOP of the box with all your launchers and you'll see the word "Arrow:" and a drop down box that says "Default". Click on it and select the bottom option "Inside Button" then hit OK.

If all went well, your customized app launcher should be complete. More than one can be created if you wish to group certain apps together and any Application Icon can serve as the button.  You can go back into the "Properties" of your app launcher at any time and, change the ordering the apps using the up and down green arrows.

Enjoy!

-Nolarut