One of the great things about standards is that once they're widely adopted people can bend them to uses that were never thought of by the people who originally crafted the standard.  Everyone knows you can get news and blog posts via RSS, but there are a lot of other potential uses as well.  I've been noticing many different types of data available as RSS and ATOM lately, so I've decided to compile a quick hit list of my favorite alternative and uncommon uses of syndicated data:

1. Track Referrers.  If you have a blog or a public Website, you're probably very interested in who's sending you traffic.  What better way to get that information than in an RSS feed that you can put on your home page?
2. Keep Track of What Bloggers Are Saying.  You can stay on top of what people are saying about you, your company, or anything else by doing a Google Blog Search or a Technorati search and snagging the feed.
3. See Your Calendar Events.  If you're used to the "Outlook Today" view in Outlook, this is a great way to mimick that functionality without using Outlook.  This functionality is also supported by Google Calendar and 30Boxes.
4. Track the Weather.  A great use of realtime data in a feed.  Get your local weather in your RSS reader, or put it on your home page.
5. Watch Airport Delays.  Another realtime feed.  Weather, among about a billion other things including toothpaste and hair gel, can cause travel delays.  If you travel a lot you need to subscribe to airport delays so you don't end up spending the night in the airport.  (By the way, when will some smart company start offering nap pods at airports?  I gaurantee there would be lines of people waiting for these.)
6. Track Shipments.  If, like me, you wait until the last minute to buy your Christmas presents, you may want to track the shipments to your door.  This site helps you set up a feed for your DHL, Fedex, UPS, or USPS shipment.
7. Keep an Eye on the Latest Deals.  If you're stumped for a Christmas present, you might want to subscribe to a feed that'll show you the latest deals.  There are tons of these, also available from Orbitz (for travel deals), eBay (for auctions), and a myriad of other sites for general online shopping.
8. Educate Yourself.  If you're interested in a particular topic, syndication is a great way to not only keep up on the news but also to learn.  You can get recipes, quotes, how-to articles, and word definitions via feeds, not to mention great articles on every topic under the sun.
9. Entertain Yourself.  You can get comics, videos, and jokes in feeds.  If you want to get a little geeky with it, combine BitTorrent with RSS to subscribe to TV shows.
10. Read Email.  If you're like me, you only check email at regular intervals throughout the day, but you visit your homepage much more often.  It might be a good idea to turn your most important emails into an RSS feed so you spot them immediately.
11. Watch Traffic.  You might want to check this feed before you leave for work in the morning.
12. Get Your Reports.  Getting reports via email is so 1999.  All the cool kids are getting their data in an RSS feed now.  The best thing about this is that it enables you to get any of your internal data as a syndicated feed regardless of what it actually is.  (Disclaimer:  This is a link to my company, Latigent :)
13. Create a customized feed.  So all this data is available as RSS, but do you really want to subscribe to 12 more feeds?  Probably not, so why not just create one new feed that has everything you want?  This great tool will not only let you combine multiple feeds into one, but also filter by keyword at the same time.

Right now RSS is still not something the average person is aware of, but I think the tipping point is coming fairly quickly when it will make its way into the public conciousness.  My guess is that 2007 is the year you'll start hearing "go to our Web site and subscribe to our feed" used in commercials on the radio and TV just as we've already seen URL's plastered everywhere you see an advertisement.  Once marketing folks figure out syndication is basically just building an opt-in mailing list in reverse they'll realize its their best friend, and there will be no escaping "subscribe to our feed".