Twitter is a free social messaging utility for staying connected in real-time. Listed below are the "Twitter Websites" of the Exergaming / Active Gaming Industry:

Interactive fitness and Exergame Network - http://twitter.com/ExergameNetwork  

Gamercize (Richard Coshott) - http://twitter.com/activegamer

Exergame Fitness USA (Tommy Seilheimer) - http://www.twitter.com/exergamefitness

XRTainment Zone (Dr. Ernie Medina) - http://twitter.com/XRGamer1

Be Fit with Biray (Biray Alsac) - http://twitter.com/Befitt 

Exergame Lab (Stephen Yang) - http://twitter.com/syangman

Fitspott (Dave Gise) - http://twitter.com/Fitspott

Exergaming Finland/Australia (Brett Young) - http://twitter.com/Exergamer

Alasdair Thin (Scotland) - http://twitter.com/Gamersize