The reason your friends aren't begging you for a Google Voice invite is probably 'cause they've got one by now. BusinessWeek got a hold of the redacted user numbers Google gave to the FCC, and they're higher than I'd expect: 1.419 million users, only 570,000 of whom actually use it everyday.
Maybe the more interesting, number though, is how many companies it takes to make Google Voice happen:
In its correspondence with the FCC, Google also reveals several companies that help it provide Google Voice. The list includes fiber-optic network operators Level 3 Communications (LVLT) and Global Crossing (GLBC). It also mentions Broadvox Communications, Bandwidth.com, and Pac-West Telecomm. IBasis (IBAS) is responsible for connecting outbound international calls on Google Voice and Neustar (NSR) provides "porting and carrier lookup services," Google says in the letter. Syniverse Technologies (SVR) provides the free text-messaging service.
That's eight, not counting Google itself. [BusinessWeek]