***～会飞的蝎子～学习宁静致远

Finance: Both Google Finance and Yahoo! Finance let you get finance news updates for specific companies and stocks, just look for orange "Subscribe" or "RSS" icons in your browser. To receive stock quotes (only for some stocks), you can use NASDAQ's feeds.

Weather: You can get weather updates from The Weather Channel, WeatherBug, or NOAA's National Weather Service.

Classifieds: As Gary mentioned, both craigslist and Oodle.com offer feeds for all of their listings. Just look for the orange "RSS" link at the bottom of any results page -- when you subscribe to a search, for, say, apartments under 00 in Manhattan, you'll get updates when there are new apartments matching that search. Similarly, in eBay you can find an RSS link at the bottom of any search page, and in Google Base near the top-right corner.

Package tracking: If you'd like to track packages that have been sent by UPS, FedEx, USPS or DHL/Airborne, you can use isnoop.net's universal package tracking or simpletracking.com.

Social networking: Facebook offers feeds for many of its features; you can see notifications, status updates, and your friends' posted items in Reader, as explained on this page. For those of you that are Twitter fans, you can get RSS feeds for many of its pages.

Shopping: Amazon lets you get feeds for the latest popular products as well as wish lists (look for the orange feed icon). Many other shopping web sites offer feeds, including Yahoo! Shopping, MSN Shopping, and NexTag.

Saved searches: Google Blog Search, Google News and most Yahoo! sites (among others) let you subscribe to search results as feeds. This way, if you want to monitor a topic, you don't have to keep running searches over and over again.