i just downloaded and watched hype which came out in 2001. don't know what time period the footage is from (parks is wearing gloves in it like he is in the shafted films). it surprised me to see the double half cab in hype. it put the complaints i've heard from folks about that move in a new light. i didn't realize he'd been throwing the move for that long.
blake, as far as i know no one else is doing or has tried that trick. here's what i know of folks attempting or making double inverts:
gerry nunn: double back roll (done)
daniel watkins: double back roll (done)
darin shapiro: double front flip (done)
triple front flip (attempts - tho he claims to have landed one not on video)
parks: double back roll (done)
double tantrum (done)
half cab double back roll (done)
switch double back roll mobius (done)
dallas?: double ts front roll (attempts) these are in one of bame's films - i think shafted, but i can't remember.
and joe -
murray: double back roll (attempts)
you can see murray's attemps in dave's videos (http://www.dpcfilms.com/videos.asp
, and also in hype.