I was given the book collector software for christmas with a scanner. I suspect this was fairly expensive, but it was worth it. I got 600 done in a couple of hours. I have a fairly esoteric collection so it will only do about half in fully automatic mode, but it will be a massive time saver even for the manual ones. I recommend it. That said I have not yet had a look at Library thing so I do not know how it would compare.

Best of luck,
Rufus