Is there anywhere that I can download some of the player graphics from RBI?
Forgive me for being Captain Obvious, but it seems to me that you could right-click the picture under your name and select "Save Image As...". If you want more, you could go through the whole list of forum avatars, as there are several RBI players, I think.
Apart from that, though, I have no idea.
I don't know of anywhere to download pre-made RBI graphics. However, it shouldn't be tough to use any tile editor you like and paste or recreate the tiles in a graphics program.
Nightwulf