RSS Feed Authoring Tool
Duncan MacKenzie created a tool to create an RSS 2.0 file from user entered data rather than as a feed from a blogging engine. Sometimes you have content that you want a feed for without it necessarily being in your blogging engine. Duncan created this for use on MSDN, so that some of they're article headlines could be in an RSS feed even if they weren't in the content management system.
It's pretty cool, so if you need to produce RSS files for content outside of a blogging engine, this could be useful.