Go here http://prius.gpotato.com/ Click on the CBT signups pic and a survey box should pop up.
Fill out the survey, check your email for cbt key and activation link http://prius.gpotato.com/?m=cbt

More info and CBT key giveaways can be found here. http://prius-forum.gpotato.com/viewtopic.php?f=5&t=327

Territory coverage/ip blockage info here. http://prius-forum.gpotato.com/viewtopic.php?f=5&t=276