Post to Multiple WordPress Blogs at Once with Multipost Plugin
The Multipost MU plugin has been around for over a year but has recently been updated for WordPress 3.0 so that you can use it on your Multisite network. It adds an extra box to your “Edit Post” and “Add New Post” screens where you can elect the blogs where you want the new item posted. If the “master post/page” is edited or deleted, all multiposted copies will also be edited or deleted. This is a handy tool for anyone running a Multisite network where you want to get a post out on multiple domains at the same time.