If you are in London and someone tells that you look really smart, he's probably referring to your look.
However if a yankee tells you the same, you should feel quite proud 'cause he's appreciating your intellect. Ok... a question rises, what about merging the two meanings? Ehm...actually I don't know the answer but I think it could be in some sense connected to smart clothes or something like that. Nowadays this in not a completely weird concept. I'm talking about wearable computing, that is, we'll dress up not only common cotton, wool, etc, but also chips, silicon and other interesting stuff.
For Italian people a nice article can be found on Tasc .
