I think what you're looking for is Aluminum tape, used to hold ducts together. It's great stuff and I find it sticks to ANYTHING.

You can find it at hardware stores such as Lowe's and Home Depot. Here's a link to some from one of their sites.

Aluminium Foil Tape

You can also buy it from The Bean Farm. You will find it under their Heating section on the bottom of the page

I've found the cheapest place to get it is at the hardware store. There are a couple different thicknesses. i've always used the thinner stuff and usually find a roll for around $6