Daytona USA is cheap and fun =) Coincidentally I need to get a new copy mine was pretty beaten up when I got it and suffers from music skipping from time to time =/
Daytona USA Championship Circuit Edition also good =)
Battle Arena Toshinden Remix is an interesting title that can be found cheap, definitely not the best fighting game around but I think its worth a few dollars just for the comedic value of the cutscenes, they're so bad they're fun =D
When NASA first started sending up astronauts, they quickly discovered that ballpoint pens would not work in zero gravity. To combat the problem, NASA scientists spent a decade and $12 billion to develop a pen that writes in zero gravity, upside down, underwater, on almost any surface including glass and at temperatures ranging from below freezing to 300 C. The Russians used a pencil.