Keep in mind the option of getting a good digital camera, like a Canon or Olympus model.  12 megapixels or higher tend to provide great resolution quality.  Pay the extra couple of dollars to get a camera with digital picture stabilization and autofocus features to make life easy. 

Online stores like Amazon and BestBuy are good for ordering them, if you don't have a big box store local to you. 

Use consumer reports to compare prices and analayze features beforehand.

This provides portable flexibility and ease of carrying that few scanners can offer (and yes, I do have a portable "bar"-style scanner, but a camera is far more functional in most offices I go to).