OPML is a file that can be imported/exported, uploaded/downloaded that contains all of your RSS feed information. I've talked about RSS feeds before. RSS feeds are an invaluable tool for the 'internet addict'. I've thought about sharing my list of RSS feeds for a while, but haven't been sure about how to do this.
At Share Your OPML.org you can upload your list of RSS feeds, and then view those feeds that are similar to your own.
I highly recommend it.