With the explosion of the social web, it's becoming increasingly common for each of our online activities -- such as uploading a photo, publishing a blog entry, bookmarking a web page, or listening to music -- to leave its own digital trail (usually in the form of a timestamped RSS feed). The problem is that each trail lives in a different location on the net. However, a number of web services exist which make it possible to aggregate this data, to display a chronological view of a user's online activities -- a concept commonly referred to as 'Lifestreaming'.
iStalkr, which is currently in Beta, pulls in the RSS or Atom feeds of popular social web services such as Digg, Delicious, Flickr, Last.fm, and Tumblr -- or, in fact, any publicly viewable feed -- to create a visual time line of a user's activities which can then be published onto a blog or elsewhere on the web. Additionally, a user can monitor their friends' time lines.
The Twitter-like micro-blogging sercice, Jaiku, also offers lifestreaming functionality by making it possible to pull in updates from any social web service that provides an RSS feed. So whereas iStalkr simply aggregates third party data (which could include a Twitter feed), Jaiku acts as both aggregator and publisher -- by also allowing users to post and receive status updates (such at what they're doing, availability, and location) from a mobile phone -- hence the Twitter comparison.
If you're interested in finding our more about lifestreaming, check out The Lifestream blog, written by Mark Krynsky.
Related post: Spokeo, a social network aggregator