With all the hype surrounding the price drop of the HP TouchPad, I have found myself spending a lot of time trying to find a store with one in stock. At one point I saw that HP's own store listed the touchpad as "coming soon" after most stores had run out of stock. Instead of refreshing the page on my own I wrote a script to do it for me.
This script loads the product page every 30 seconds and checks the button area to see if it still says coming soon or if it has the out of stock image. When it no longer finds either of those things, it has my computer say "alert" over and over again (in an australian accent, because who doesn't change their speech voice to australian) and automatically loads the product page in Chrome Canary for me.
I'm sure there are many others like it, but this one is mine. Check it out. Use it, fork it, modify it for your own needs. I license this under WTFPL.