Depends on what I am up too. I use an encrypted version of firefox run from an Ironkey thumbdrive (see
www.thinkgeek.com for this item...but only if you are in the U.S.) and I bounce between firefox and IE otherwise...some websights like firefox...some dont.
Fortunatly alot more sites are catching on that not everyone likes to use a laggy "I track and store waht you look at for YOU and not everyone accessing your computer when you dont know" microsoft product.