I came across this very useful shortcut (CTRL+SHIFT+R) by accident. I was working on a ship, where I setup a small network with a Mobile Broadband connection. I noticed that all the graphics where downgraded to a lower resolution, which in some aspect is good as it saves bandwidth usage, but sometimes I wanted to bypass that and Firefox just gave me the answer. While looking at one specific pic I moved the mouse over it and a message came up telling me to use the shortcut (CTRL+SHIFT+R) in order to see the pic in it’s true resolution, I did it an dit worked.
After that I researched the shotcut and found this page with not just this one but the most used Firefox and IE shortcuts. URL:http://www.mozilla.org/support/firefox/keyboard
I find this shortcut very useful, especially when working on a website where sometimes just a simple refresh doesn’t show the changes you’ve made. This shortcut overrides the cache forcing the page to reaload from the source instead of relying on the cache (local or remote).
Reload (override cache)
CTRL+SHIFT+R for Firefox
CTRL+F5 for IE