If you want 480p RGB (VGA) you can look for these on E-Bay: (1) an Aims Lab Instant TV, estimated price USD 50, or a Silicon Image iScan Plus, estimated price USD 225.
If you want something new, tehre is the VB50, I forget the maker, or (superb) an iScan Pro.
Video hints: http://members.aol.com/ajaynejr/video.htm