Dear Dopplr,
I just read about you on Tara Hunt’s blog (the screenshot was the kicker), and you sound cool. As somebody who travels a lot and is smoking the Web 2.0 devilgrass, I think your service might come in really handy.
Unfortunately, I hear you’re being really frugal with your invitations. What’s with that? Exclusivity is so Orkut, and inclusiveness is the new black. Throw those doors wide open, and let the masses come piling in. If that happens, it’ll be a nice problem to have. If not, then just send me an invitation because I want to become a passionate user of Dopplr.
Your Webby Friend,
Darren Barefoot
DarrenBarefoot.com 
lol – brilliant! must try that style next!
“Dear Die Hard: you rock!”
Every time I think DB is sane, he starts writing letters to web services again.
Did you see my invite? I notice you haven’t accepted yet…
Tara: Thanks very much for your invite. I’m going to check it out next week, once the Magic Internet Man connects our Web Juice pipe next week.