Nowadays, it is rare that any website does not have rss feed . Hence most of the times I tend to subscribe the feed so as to track it forever. This works well for dynamic content. However there are umpteen number of instances where we want to keep track of few static pages. The solution ,generally followed is to store it in browser favorites.
There are 2 drawbacks with this approach:
1. If I move to a different machine, I should take of copy of fav and include it in my new machine
2. I can never know who all have visited this page on the net, which means I cannot judge the popularity of the URL I am browsing.

To address the above 2 problems , a slew of sites have recently hit the market. My favorite being http://del.icio.us where one needs to add an icon to the browser after which one can tag a webpage on the net. The tagging helps in knowing who all have visited the same page and stored at del.icio.us. The homepage of the site also gives the most popular tags from which one can also view the most viewed web page on a specific topic.

Apart from del.icio.us,there is http://wists.com where one can have a visual description of each of the favorites.A mix of del.icio.us and Technorati will give a good idea about the real-time web.