When Google Voice launched in March, it was only available to people who were already subscribing to the service Grand Central, the company that Google bought and turned into Voice (also a pain since getting a Grand Central account wasn't always easy).
Finally, though, Google Voice is now being opened up to anyone. Of course, you still have to request an invite, which I personally just did, because it just seems worth it for the free call management system (you get a single number that can ring multiple lines, an Internet-based voice mail system, and you can make Skype-like calls over the Internet).
It does seem like a lot of hoops initially, but I know a lot of geeks are lining up for Google Voice. Are you?