Can you add remote files to your library?

I use Songbird exclusively for playing remote files on the web. It certainly works great for this but after a while I started to want to create playlists and especially use Smart Playlists.

I was a bit surprised to see that apparently you can't add remote files to your library. But I'm really disappointed to see that it seems Songbird used to support this!

There were two possible solutions I found after some searching - adding files one by one using "Open Location," or an add-on that restores the "Web Media History" to the left side bar. The add-on doesn't seem to work with the current Songbird, and I can't get any songs to work through Open Location ... it gives a "could not read from URL" error when I attempt to play it. However, the same files work by just browsing to them and playing them in the interface. (Possibly because it's behind HTTP authentication?)

At this point I'd love to have even the clunkiest and slowest way of doing this, but at the moment it seems to be impossible.