GeoRSS

This site describes a number of ways to encode location in RSS feeds. As RSS becomes more and more prevalent as a way to publish and share information, it becomes increasingly important that location is described in an interoperable manner so that applications can request, aggregate, share and map geographically tagged feeds.

To avoid the fragmentation of language that has occurred in RSS and other Web information encoding efforts, we have created this site to promote a relatively small number of encodings that meet the needs of a wide range of communities. By building these encodings on a common information model, we hope to promote interoperability and "upwards-compatibility" across encodings.

"TagCloud is an automated Folksonomy tool. Essentially, TagCloud searches any number of RSS feeds you specify, extracts keywords from the content and lists them according to prevalence within the RSS feeds."

Check this out. Feedburner has added this really cool feature to their feeds, which allows you to email, or tag to delicious, an item directly from your feedreader. From techcrunch.