I just picked one of these up because my PB becomes a stove on the bottom of it when I use it for extended periods of time. I could only find one store online that had them and I got this thing QUICK. Well I will highly recommend it. I will take some pics tomorrow to show you how it fits but this thing keeps my PB nice and cool and it has four more USB ports on it because it uses one to power the fans. Here is the product:
http://www.targus.com/us/product_details.asp?sku=AWE01US
http://www.targus.com/us/product_details.asp?sku=AWE01US