Unshruggables

Unshruggables (N): People you can't seem to get rid off

I met one today.. I was getting back from the airport by bus and he chanced to sit next to me. He seemed plain friendly at first and then went on to trying being pally. He rambled on for the 25 minutes that the first connection from the airport took. Believe me when I tell, you I was answering in monosyllables and said no more than 10 words. I was in no mood to fraternize with overly friendly strangers. He got off at the same stop as I did and waited for the same connection bus I did. I have never had a longer 45 minutes in my life. And it wasn't like he was talking about the weather. He was probing about me.. what I did.. where was I from.. how long was I here... I even went so far as to tell him, "I don't think I need to answer any of these questions." And finally I managed to shrug him off by getting off a stop later than I wanted to. The things one has to do... Whats the politest way of being rude? Any suggestions to deal with such situations?