Maybe you've already implemented this, but I'm using 2.3.3 and I haven't found it. Anyways, here's the idea: automated search and download. Essentially, you put in some parameters (file\artist name, format, bitrate, etc.), and it would continue looking\regular search (say every 3 minutes) for the file and automatically download it even if the file could not initially be found on the network.

For example: I'm looking for Joe Unknown - Obscure Track.mp3. After doing a quick search manually, nothing shows up on the network. So I put in the artist name, format, and minimum bitrate into an automated search and download, then go watch tv for a few hours. About an hour after I leave, Jane Doe comes online and happens to be sharing that file. The automated search and download takes another poll, finds it, and downloads it. I come back in another hour and look at the screen showing my track automagickly downloaded with a big dumb grin on my face and put on my headphones. (-8

This could also have the side effect of encouraging people to stay on the network longer, which would mean more files being shared...

Just an idea.