Compared to Dustin's though, both of those hurt my eyes to look at. This reminds me of Posterous, blogging is a crowded market but they differentiated themselves by being beautiful and dead simple. Competitors are good, it just proves that there's a market for a service like this.
I love the idea of a printed letter API (like what postful.com has) as a solution to send automated letters to people. First one that comes to mind is to send a letter to someone if they do a chargeback or their credit card was declined.
I look forward to implementing something like this!
http://www.postful.com/ http://www.l-mail.com/
Both look pretty clean and offer various capabilities to send lots of letters more efficiently, including an API.