I just came across this nifty little Firefox trick that is sure to drive some of your friends crazy! As seen in the screenshot above you can very easily embed multiple Firefox windows inside of your main Firefox window. All you have to do is enter this into the Firefox address bar and press Enter:
The usefulness of this trick is probably next to nothing, but it will surely drive your friends crazy when they see their Firefox looking like the screenshot above! If you set their homepage to the address listed above it will automatically create a second Firefox window, but from what I can tell you can’t make it create multiple windows inside of windows like I did above without manually typing in the address into each address field.
Make sure you let us know any good tricks you pull with this one. :)