tchristensen81, I gotta give props for bringing ReGenesis back to my attention. It was one of the first transformation stories I encountered.
There's a LOT of amateur tongue trick videos on Youtube. The quality varies dramatically and unfortunately the 'Related Videos' function thinks tongue videos belong in between men doing disturbing facial contortions and news reports about the world's fattest child, so wading in there is not for the faint of heart, but here are some good ones:
<- teenaged girl's tongue literally
dances.
<- a public exhibition
<- very amateur, yet very fun
<- almost pornography
Also, this strip from the webcomic
Wapsi Square is probably of interest:
HE LUBBS MY TUMB!