I just came across this by accident, because I am about to start converting my entire sheet library into pdf files, and I have been hunting for a good dedicated scanner...
This app is called Turboscan for iOS, costs 2.99 and I attach an example of a scan I did with my iPad 3 camera (apparently the iPad 2 camera doesn't give as good a result) so those with iPad 2 or 1, should probably use the iPhone to take the pic...
Now this is my first attempt so it is a bit dodgy, but with practice it should get better I think, but this may be a really cheap solution.
Took a second to take the pic, another couple to do minor adjustment and then just sent it straight to a pdf file (it also can use other formats I think)..
Anyway, just thought I would share the discovery. For those who already know about it, sorry
Dennis
PS: Don't confuse this app with a similar one called Turbo Scanner, which is apparently VERY dodgy..make sure it is TurboScan