Xyron Adhesive 2 Inch by 2 Inch Eraser
From Xyron

This square eraser removes most adhesive residue. Acid free quick and easy removes misplaced adhesives and is non-toxic. Perfect for school and home projects scrapbooking and paper crafts and card making. It mesaures 2-inch by 2-inch.

Amazon Sales Rank: #76545 in Kitchen & Housewares
Brand: Xyron
Model: 23675
Dimensions: 5.35" h x 3.85" w x .45" l, .10 pounds

A great picker-upper
I don't have the xyron version of this, but I'd imagine they're all similar. Rub the corner of the eraser over an area with unwanted adhesive in gentle circles and it will pick it up. This works best with repositionable or tacky glues, some of the permanant glues require more work to remove.

It really works!
I bought this item, skeptical of how it would perform. I'm happy to say that it really DOES erase adhesive, easily and completely with very little effort! I highly recommend this product!