Google Alerts

What it does: 

Sends you an email alert when Google finds a new result containing the search term you've supplied them.

When to use it: 

When you are monitoring a news story or to keep on top of an issue.

When not to use it: 

If you are not going to be checking your email regularly.


Its fairly comprehensive and will let you know about content posted on the web that you otherwise wouldn't have noticed


It won't alert you the moment that something has been posted.