While at Micro Center today, I stumbled across a bunch of surplus webcams: Microsoft LiveCam VX-1000 USB units in black and gray for 20 bucks each. They're focusable, which means I could actually try to use them in one of the programs.
I settled on Media Man 3. It's pretty simple to use, and it works with the webcam nicely. There are some issues: about 85% of the time it reads the code and identifies it fine, but the rest of the time is split between unreadable UPC codes and mismatched ones. The unreadable ones I can type in manually; the mismatched ones I have to do a title search.
Still, it's nice to finally start getting them sorted.
It also can catalog Blu-Ray discs, CDs, paperbacks, videogames, and probably a few other things I haven't tried yet. Seems like it may be limited to a tie-in with Amazon.com.