What is this 11x6 white and dark grey motorized LEGO piece with blue buttons and a transparent blue panel? My brother bought a big tub of LEGO recently and found this piece inside. He doesn't know what it is and we can't find anything about it online so we were wondering what it is. He says it isn't in any of the instruction booklets he received with the LEGO so it doesn't seem to be a part of any of his sets.
It appears to be a motor, with a white front, grey back, a display and blue buttons. When you turn it on it displays the word LEGO one letter at a time on the display. It also makes sound by bleeping and stuff when you turn it on and as it runs.

It has the LEGO logo in each of the holes and underneath so we assume it's an authentic LEGO piece, but it doesn't have any sort of identification number on it that we can see.

Thanks for the help.
This part is called

Micro Scout with Dark Gray Base  



the white version on your photo comes from 

9748-1: Droid Developer Kit  

  

(pictures via Bricklink)