is there a portable version of songbird?

It can run portably, but when you download a music or add music files to your library you can't remove them later, also if the full path to %profile%\db changes (ie: D:\PortableSongbird\Data\Profile\db on one computer and E:\PortableSongbird\Data\Profile\db on another where the usb stick uses another drive letter) songbird will not look for the databases in the new path, but it will look in the old, wich doesn't exist. So it will run portably, but the library will disappear. ( Delete or Edit for 15 minutes )

Oh, yeah.
I've got VLC portable for quick listens but if i want an extended play i will use Songbird. To set up Songbird on a new computer, I just have it re-scan my library. It takes a little time but is well worth it.

I don't use playlists and assume they won't carry over well... ( Delete or Edit for 15 minutes )

You're missing a few things. You don't want to leave traces of Songbird on computers you've used the portable version on so you'll need to remove the registry entries it creates and remove the Application Data folder under user settings.

To track what registry entries it adds you can use regshot, there's probably another app to track what other folder dependencies it creates. I've used one to do a full system snapshot to see watch for folder/file modifications but I can't remember what it's called.

If you're only using this on your own private PCs, you don't have to worry about it. If not, you might want to wait for the PortableApps Version. ( Delete or Edit for 15 minutes )