Sometimes you're on the go, and you need to send someone a document that you have only in paper format. Some of us don't have a scanner or fax machine at home, and want to be able to digitize all of our bills, paperwork, and pesky documents. Enter the cell phone scanner app.
CamScanner by IntSig, and many of its competitors, are popping up on the Android Market, in the iOS App Store, and for other phone models like Blackberry and Windows Phone.
Personally I've had very good results with the aforementioned CamScanner, which allows taking the shot with or without a flash, cropping and rotating the image, and a multitude of sharing options - like uploading to Google Docs, Evernote, and Dropbox (yep, there we go again).