I have access t some plastic type deadener it is really odd looking stuff though. I beleive it is a thermoplastic dampener, I used it along with spray noise killer and dynamat super (I got that for free :p )
On another note KnuKonceptz.com will be releasing its own version of KnoKnoise or K.O.Knoise (name has yet to be decided...lol) in mid summer, its unlike any other deadener I have seen, its a combination of aluminum backing and a gooey polymer that stickes to itself, its actually cool looking stuff and will hold better than any glue backed deadener since the polymer will be doing all the bonding.