"3. Wikipedia Extension
This add-on should come in handy if you want to check out
information of the song's artist. The Wikipedia entry is by default
displayed at the bottom content pane.
"4. iPod Device Support
This is a must-have extension for iPod owners, as this will give
Songbird the ability to sync songs from its media library to the
iPod. Once the iPod is mounted, you will also be able to play songs
from the device playlist."