If you frequent websites where the pages are constantly updated and you have to click the refresh button to get the latest information, rather than manually clicking it yourself, check out the ReloadEvery Firefox add-on.

Reloads web pages every so many seconds or minutes. The function is accessible via the context menu (menu you get when you right click on a web page) or via a drop down menu on the reload button

This add-on is very useful for sport scores and stock quotes (just to name a few) but it will work on any page. Simple, but very useful.