I went to a community college that had 35mm scanners on their computers and they worked great. Now all I can find are photo scanners with an extra tray for negatives. I hate to recommend something I haven't used and can't find reviews about, but nobody else has posted anything yet so maybe this will get you started. You're looking at $189.99 for the Epson.

go to www.pricewatch.com
under "peripherals," click "scanners"
in the center, column click "negative scanners"