I'm getting ready to do this very soon too...

To download multiple tracks, simply select a folder or multiple tracks and right click to download (running 2.00beta11).

But Jemplode is a bit better about how it downloads. You can specify how you want the files named... This will allow you to by-pass the limitation mentioned in the FAQ. when you use something like MP3 Tag Studio. If your tags were pretty accurate prior to uploading, this probably wont be a big concern for you.

When you say "another computer" do you mean that you have the collection on 2 PC's and the Rio too?