PaFlyFisher...

if it plastic or latex it can be used..

for instance..I have used..
plastic:
scudback.. from the fly shop (I think its more like latex)
thinskin.. from the fly shop (I think its more like latex)
the plastic off wrapping papper (X-mas or Bday)
plastic off boxes
sulaphin (sp?) from cigarette packs
any kind of plastic baggies
window plastic (when you cover your windows in the winter) NOTE: if you use the shrink kind.. clean your bench before starting the hair dryer.. I found this out the hard way!!LOL
as far as latex..
gloves,(sorry if this offends anyone).. But I have even used condoms (any color, just the non-lubicated workes the best.

Just about anything really can be use..

Hope this helps with some ideas for you