They're ramping up the Gmail beta user base. To help out, we issued some invites to Blogger users. If you're an active Blogger user (by some definition I'm not sure what is), and you'd like to try Gmail, just log in. (If you're like me and use BlogThis! all the time, you might not notice. You need to go to the home page.) If a "Special Notice" inviting you to try Gmail appears above your list of blogs, you're a lucky winner (if not, please be patient :).
BTW: You won't get the link if you just go and sign up now -- or if you haven't been using Blogger recently. Sorry.