You were also able to post messages through a web form from the Posterous website. It makes it very easy to post a message correctly without having to worry about what e-mail you're sending the message from. It has a simple airfare use without a lot of extra capabilities, and if you are only needing to send a simple message then this should work just fine.
What I don't see, is the ability to insert images easily or videos. I do put a lot of rich information into my posts so this will probably not work for me in a day and day out usage. However, if you need quick documentation of things that you were doing, or status updates that misapplication should work just fine.