One thing that I have really missed in playing with songbird is Global Hotkeys for changing the song, etc. This functionality is available for Windows, but Linux (and Mac) users still have to wait if we want official support. There is a workaround, though, thanks to GeekShadow's addon Command Line Support. This allows for all kinds of clever hackery, including global Hotkeys.
This tutorial is for Ubuntu Linux specifically, but might well apply to other linux distros with Gnome, and the principals are certainly globally applicable.
First, get the Command Line Support addon
Navigate to http://addons.songbirdnest.com/addons/1381 in songbird's browser, and you can install it cleanly. Otherwise, you can download the .xpi file, and open it with songbird.
Now to create the shortcuts
In the "Keyboard Shortcuts" dialog, click "Add"
Fill "Songbird Next" for the name, and "songbird -next" for the command
Note: the "songbird -next" command will only work if the command "songbird" works on your command-line. If you have Songbird installed someplace special. use for your command "/path/to/Songbird/songbird -next".
Finally, enter a key combination to bind to the command. Repeat for -prev and -pause
Done!