Yeah, actually, wouldn't any gel pen work? I know they make black paper for them.
Personally, I like silver or gold markers (mine are made by Pilot). You can get them at Staples or any other office supply store. They're nifty. My boyfriend's band all bought them when their album came out, cos I made the cover black (I designed their album). Looked spiffy signed.
Oh, but there's one bad thing about them. If you touch the signature/writing before it's dry (they're like paint markers), it smears. Bad. Although, you can get someone's thumb print really easily, which could be kinda fun with a celebrity.
