PLANon DocuPen RC800 Portable Scanner
 

he scanner is equipped with a red X indicator that informs the user when the scanner is being moved to fast. We found that the light only came on when we moved the scanner to fast during color copies at high resolution, otherwise we were able to scan an entire 8x10 page in about 7-8 seconds.

http://www.techwarelabs.com/reviews/peripherals/rc800/