Just a quick note for those of you wanting a 64bit version of Firefox!
You can obtain a 64bit version here! For those of you that are daring, download and install Firefox.next (version is based on a time stamp).
For those wanting something that works, you should download a version after the list of files for Firefox.next (e.g. Firefox 3.6 below).
JAVA is available (and more stable from what I can tell) in 64bit flavors and I would recommend installing a 64bit version after installing a 64 bit version of Firefox
Note that Flash is not available for 64 bit browsers yet (unless you are on linux).