Where is the favorites folder in Firefox?

As the titles says where is it? I want to make a back up of it.

well you can do it two ways. Bookmarks tab manage bookmarks file export pick a spot and save or

C:/Documents and Settings/Your Username/Application Data/Mozilla/Firefox/Profiles/letters and numbers.default

files is bookmarks.html

Ok cool. Also what if i ever decided to go to the dark side (IE) Will i be able to use the firefox favorites?