Aggregator Ping Plugin
Russell Brown has created a plugin called Feed Ping to automatically ping your favorite blog and news aggregators when you create a post. This notifies the aggregators to retrieve the new content so that it will immediately appear in their site.
This is a feature that several people have asked for, so I am glad to see people contributing plugins that check items off my to-do list. :)
More information at Russell's website. Thank you, Russell!