As all Knows Firefox is great browser, i always recommend to use firefox. since it has lots of features. Here are some cool tricks that We all should know While using firefox.

1. Session Restore
This feature provides you to access the your accidentally closed Tabs. Simply go to history and select your page that was closed Accidentally from Recently closed windows.

2. Using Firefox to Calculate
Sorry, you are not using firefox as Calculator, but you can use the search box at the Top right side of Firefox. The Default search engine is Google and some of you has tried google search engine acts as a Calculator. So to Calculate Simply Enter the expression(521 + 845) in the Search box and search you get the result. Wow.

3. Firefox Magnifier
Are your eyes paining due lot lots of reading in the 1024 by 768 or any higher Resolution?
i am not going to say to reduce resolution of your screen. nor use that windows old magnifier. Firefox has its own magnifier.
How to :
i. Zoom in : CTRL (key)and at same time use plus key
ii. Zoom out : CTRL(key) and minus key
iii. Normal : CTRL(KEY) And 0 (Zero key)

4. Multiple Homepage
I am a Regular orkut,gmail user whenever i come online first i visit them. Each time i need to enter atleast one address to visit. but firefox has multiple homepage. Simply in the home page setting use the ORing operator '|' - pipe. between two addresses