They're called "film scanners." This'll get you started.
http://www.scantips.com/basic13f.html
You probably want to get one with an infrared channel for automated dust removal.
Most of the digital photography sites have reviews. Here's one
http://www.imaging-resource.com/SCAN1.HTM
It's probably easiest to buy them online from the big electronics and photo dealers.
It's worth checking out Vuescan:
http://www.hamrick.com/vsm.html