Yes, Jeanie is right, Vuescan is a standalone program. I think Photoshop looks for Twain drivers under its Import function. Vuescan doesn't use Twain.
Nice thing about Vuescan is that it doesn't mess around with the registry. If you want to get rid of it, you simply delete the directory it lives in. Unfortunately for me, there are no drivers for my flatbed and Ed Hamrick said he's not going to write any
