Google's email service. I have a few issues with it, but it offers you a gig of free space and the text ads are relatively unobstrusive. For the time being it's an invite-only membership.
I wouldn't mind getting a gmail invite, I use hotmail now and although I have no problems with it I wouldn't mind having a good backup. PM me please, thanks.
Unfortunately I handed out the 6 I had. There seems to be a few other people in this thread with invites to give away though. If you're really desperate for a gmail invite you could always ebay one. That's how I got mine - only $1.00.
But, if I get anymore invites, I'll be sure to offer 'em to anyone who wants one.