I've kind of been toying around with getting a GURPS 4e game going in Battlegrounds RPG, if I ever get off my behind and start putting it together, I'll make a post about it here. I have 5 floating licenses (in addition to my main GM license), so nobody else would need to license to play.

The thought I'd had was to use e-mail for everything but combat, and then Skype+Battleground RPG for the actual combats.