I just had a play around and built a trivial Spotify album search engine.
A Spotify album search engine
I built it because I said yesterday I would build a site in one day. This was pretty easy. Although it is a bit pants that it only searches albums. I should do more. I can do more. I might do more.
Edit: The spotify API changed slightly since I did this and I've noticed a few Notices coming through. I should clean this up a little more soon. Too busy with Full Fat Things and GeoSay right now