Google Alerts has bee around for quite a while. "Google Alerts are emails automatically sent to you when there are new Google results for your search terms." That explains what Google Alerts are.
I really find them handy. For instance, I can create an alert with my own name as the search term. Then whenever a website mentions my name Google sends me an alert in my email box. That's pretty cool. I also keep track of topics that interest me, for instance I have an alert for "Google Egypt." I'm able to keep track of anything said on the web about this topic. Go ahead and try using Google Alerts with a search term that interests you.