Most obvious difference with firefox is you can open web pages in new "Tabs" withing the same open window. You don't have to open everything in a new window. Quite honestly IE on XP is a total pain in the neck if you have more than about 4 pages open at the same time. It is also very easy to manage the downloaded cookies in firefox. You can jst open a box in the preferences and delete individually anything you don't actually want or need (mostly anything which isn't mudcat).
Quack!
GtD.