Most of you have seen this and might not know it. It's that cool velcro on the back of our EZ-Pass transponders.
This stuff is awesome. Unlike traditional hook and loop fasteners, this stuff has little plastic "mushrooms" that interlock. It took me a while to find a place that sells it in small quantities since it's sold by 3M in 50 yd rolls for more than $400. However, BudgetRobotics.com sells it by the foot for $2.19/ft.
Remember though to double whatever length you think you need because you're only getting one side. The good news though is that it is rated to hold in excess of 50 lbs/sq in. at temperatures of up to 250 degrees. A little goes a long way.