Blog post of a great review of various website change detection services.

Check out these posts too:

  1. Free Web Services & Tools To Monitor Website Downtime
  2. Comparing the Mapping Services
  3. Ten video sharing services compared
  4. Microsoft Exchange Hosted Services
  5. Did you notice the change?
  6. Should I change or not, that's the question
  7. How do you know if a website is safe?