What's the best way to track a web page for changes to its content?

Question

I want to know how to track changes to a webpage and receive an automatic notification via email or phone.

Specific applications of this method include:

tracking ticketmaster for ticket information on a band
tracking usmint.gov for new coin offerings
tracking gamestop.com for wii and ps3 preorder info

Anyone know how to go about this?

Answer 1

Get a RSS feed of the website if available.