Reopen Closed Tabs in Firefox

For those of you who use Firefox in your Internet browsing, here is a tip I just learned from Lifehacker: if you accidentally close a tab that you still need to use, just click Shift+Ctrl+T and the last tab you closed will reopen.

I often have a dozen or more tabs open, and inevitably, close one I still need. I have used this shortcut several times in the past few days, saving me from retracing many steps.