I think I may be a little behind the early-adopter curve on this, but I just started using Google Alerts. Alerts basically monitors a given Google query and emails you when there are new pages about that topic. For example, if you want to know as soon as Google indexes a new chili recipe, you could set up an alert for "chili recipe" and you would get an email whenever Google finds a new one. Super easy.
You can even set the frequency with which you receive alerts - daily, weekly, real-time. And, you can choose to receive your emails in HTML or plain-text.
I'm ashamed to admit that I can be a little techno-narcissistic and *blush* tend to Google my own name regularly to see if anyone is referencing my blog or has written anything interesting about me. Google Alerts automates this for me! OK, enough about that...
Anyway, if you're doing research on some topic, this could be a great tool to learn about the latest sources for information on said topic.