Quick Tip: Don't use Velcro, use 3M Dual Lock (See:
http://www.itapestore.com/index.asp?...n=Custom&ID=19) It's the same stuff used on the FLL fields to hold on the Lego models. It has a higher tensile strength and has "five times the strength of standard hook and loop. Plus, since it adheres to its self you don't need to worry about having two different sides. It will also adhere to regular "loop" side velcro.
555 gets theirs from itapestore.com (direct link:
http://www.itapestore.com/index.asp?...n=Custom&ID=23)
It's also available at radio shack in small, overpriced, quantities (see:
http://www.radioshack.com/product/in...45&tab=summary)