Want FeedDemon to bring you new YouTube videos related to a specific keyword?  Here’s how:

1. View this page in FeedDemon 2, then click here to install the YouTube search definition. (NOTE: YouTube video search is built into FeedDemon 2.1, so you can skip this step unless you’re using an older version of FeedDemon)
2. Click the Subscribe button, then select “I want to create a keyword search feed” and click Next (screenshot)
3. Enter the keyword you want to match, then select “YouTube Video” from the list of search engines and click Next (screenshot)
4. Select the folder you want to place this feed in, then click Next
5. Click Finish

You’re now subscribed to an RSS feed which will bring you new videos matching your keyword (screenshot).

PS: YouTube offers a number of other RSS feeds (via Dave Winer).