Firefox Keyboard Shortcuts

To use the keyboard shortcuts hold down CTRL and press one of the following:
T = Opens a new tab and takes the focus to the new tab
O = Open Local File. This is one of the biggest changes from IE where both Ctrl-O and Ctrl-L opened a dialogue box for a URL.
L = Changes focus to the Address bar
Tab = Scrolls through the tabs from current window towards the right. Loops back to the first tab when rightmost tab is reached
1..0 The numbers 1 to 0 takes the focus to Tab 1 to 10

N = Opens a new window like IE
W = a tab or if there are no tabs, close the window
B = Open bookmark sidepanel
D = Bookmark current page
H = Brings up the history dialogue box on the right. Useful if you closed a page accidentally and forgot the URL. Or to make sure your kids are not looking at pr0n
U = Show page source
Y = Open downloads window
K = Focus goes to search bar

Some of the more common shortcuts just for the heck of it.

R = Refresh current page
F = Find in page
G = Find Again (used in conjunction with Ctrl F)
J = Page Info (same as properties in IE)
- = Decrease font size
+ = Increase font size
S = Save current page to disk
P = Print current page
A = Select All

F5 - refresh page
F6 - Same as CTRL-L, focus is taken to the address bar
CTRL Y - Open up the downloads window
CTRL K - Focus is taken to search bar