Free 1-yr Pingdom accounts - ends soon!
Dec 22, 2006
The free account allows you to monitor upto 5 sites, and you get 20 SMS credits. I just signed up, and although it hasn't collected any statistics yet, the control panel looks pretty good.
You don't need to provide credit card details during sign-up, so you don't have to worry about being charged if you forget to cancel in a year. Check it out if you maintain any blogs/sites that you want to monitor.