I actually had one of the original CueCats, which came with an issue of Wired. I went down to the RadioShack to get it. It had a PS/2 interface, though. I have no idea where it is, now.
Anyway, the one I got doesn’t seem to work with Delicious Library, a great Mac application which catalogs books, music, movies, and games. Their help page says that an appropriately modified CueCat can be used to input ISBNs and UPCs, but I’ve had no luck.