Tin foil is expensive, but definitely obtainable.LOL pretty good site Damo. But I think they are still just aluminum foil.
Tin is usually not quite so shiny.
I liked the line about signals coming in thru your teeth fillings though.
The TF hats are kinda like pet rocks though....
good business if you can find enough suckers.
http://www.advent-rm.com/items.asp?criteria=line&linenumber=SN2201