yeah im aware of noconflict but in an ideal world there wouldn't be the overhead of loading prototype to begin with! ;) (especially if you dont plan on using it at all!)
Unfortunately I don't get to play in the ideal world :( - we're doing stuff with Magento at the moment which has Prototype+Scriptaculous so deeply baked into the both the backend _and_ frontend that it's next to impossible to use another js framework with it. I've spent most of this morning trying to resolve a conflict between JQuery and their version of Scriptaculous.
Personally I can't wait to see SS move away from Prototype :).