BlogMailr. Free service which lets you post to your blog from any email client. Uses the Metablog API, so works with most blog tools such as WordPress. Interesting idea, created more as a demo platform for Telligent email gateway tech than anything else probably.
When you send an email to @blogmailr.com we first check to ensure that you are on our approved list of senders for the address you are emailing – yes we know the from address can be spoofed, but it’s step 1. Next, we attempt to take your email subject and body and make sure it’s all valid. Once we validate the email we decrypt your settings with a unique per-user encryption key and attempt to post your content to your blog. If we are able to post it we send you a reply that it was posted, if not we try a couple more times and then send you a reply letting you know what happened.