I remember when I discovered RSS feeds---no longer was I a prisoner of my lengthy bookmark list, reminding myself to check my favorite blogs. I started off populating a Bloglines account and then, like everyone else in the world, was seduced by the ease of Google Reader. But what about those sites without an RSS feed?
Previously they had dropped off my radar, but now Google Reader and other sites like ChangeDetection.com, Page2RSS, and the Firefox add-on AlertBox let me add those sites that don't have a feed and be notified when changes have been made. This comes in handy for sites without RSS feeds that keep track of academic papers and sites for which the information is time-sensitive, like setting a watch on funding opportunties.
Setting up an alert is in keeping with my favorite law of library science---save the time of the reader.