We have a large scanner / copier / printer at the office. Large and rather expensive, it carries out some basic tasks. One of my favorite features of this oversized beast is that it can scan documents and sending them to me over email. Great for expense reports!
Now you can do this using your Raspberry Pi and an old scanner instead. Eduardo Luís has come up with a solution with a single button for scan-and-email and a pair of LEDs for the status. Seems like a very convenient solution to me. All that is missing to replace the big scanner here would be a printer and a way to select where the scan would go (to who or to the printer). Still, it is 35$ and an old scanner – and it takes up less space than the office style scanner / copier / printer.