Google is now providing invites to its Google Voice service for students that have a .EDU e-mail address. Besides the fact that Google Voice is only available in the U.S., I didn’t see any other limitations of their (generous) offer. I’ve been told that Google has been sending out invites within 24 hours of the request being submitted. You can find more details on this page. Post a comment here if you’re able to take advantage of this offer.