You could access your account via the web (http://me.com) but you could not synch because the device is not an IOS-4 device. Without iCal, contacts, Apple mail etc intalled on the phone there is no way to synch.
Andecap: I spoke to soon... check this link: http://www.apple.com/mobileme/features/
I used to have a mobile me account and no longer do. It looks like the new version uses cloud technology so maybe you can actualy do it.