PageReboot provides you a bookmarklet which allows you to reload any web page after specified amount of time. Why use a automatic re loader ? Many a times you would like to see the live data on a website and if there is no provision for live update on that page, Page Reboot comes handy.
This is also useful if you keep getting address not found error and you have to manually again try it out. If you prefer to use a Firefox extension instead of this then check out FF Extension Try Again.