I really liked the solution proposed in:

Solution: How to shift the decimal
http://forum.bitcoin.org/index.php?topic=13495.0

Maybe replace uBTC with UBC for now ... eventually (when no one really uses BTC anymore because it's too annoying), we can switch over and make UBC the new BTC and the transition will be complete without anyone being confused. It just takes a little time and patience but it will fix the worst problem Bitcoin currently has (well, except for that it doesn't properly support subscriptions ;-) ).