Willow, I'm astounded that you can't see much of a difference, its about as different as you could get! They removed the menu bar by default. Buttons are no longer where they were, you have tabbed browsing etc.
Lolly, I do believe it is possible to revert(probably in Add/remove windows comonents in Control panel) but I would question the sanity of doing so. IE6 is insecure, IE7 is a heck of a lot better, IE6 will receive no further work on it and the new interface is ripped straight from Windows Vista(The new one just coming out) so you may as well get used to it now. As teh Borg say, Resistance is futile!
As others have also mentioned, try some of the other offerings, Firefox is becoming very popular(YES Kipax, we know.............
) I personally use Opera under both Windows and Linux and find it the best for me. I've used alsorts of browsers in my time and it really is a case of keep trying new ones till teh one you like suddenly jumps out at you.