We recently announced our Twitter API, which lets you use Posterous as the image hosting service inside your favorite Twitter client. Since then we've been added by over a dozen of the top Twitter clients available!
 
Today we're taking the next step and releasing our full posting and reading API. On the posting side, the API lets you post to any of your sites, including media. You can also add comments to posts.
 
For reading, you can get a feed of public posts from any Posterous site. You can also do an authenticated read, and get to private posts and private sites. This enables anyone write an exporter if you ever decide you need one. We'll never hold your content hostage.

We're also announcing our Posterous Development Google Group. Join this group to share code, get help, suggest ideas, and report bugs in the API.
 
This is just the beginning. We're committed to making the API as rich and powerful as possible, to help you write great web publishing software. If there's anything more you'd like added, please suggest it in the Google Group!
 
http://groups.google.com/group/posterous-dev
http://posterous.com/api