From their FAQ:
"Posterous lets you post things online fast using email. You email us at email@example.com and we reply instantly with your new posterous blog.
Posterous is NOT a micro blog. There's nothing micro about it! There are no limits to what you can post."
The design is slick, the ease of posting masterful. It auto resizes picture, figurest out links and video-sizing. I would consider switching over except they don't yet have the ability to natively schedule posts in advance. Currently if I post there, it auto reposts here, but not vice versa. Unfortunately, I need posts scheduled in advance because I now live in CST and I'm not normally awake at 12:01 PST.
(From a link off a link off a link at Kottke)