get up close and personal.
More about get up close and personal.
.....with a stranger.
Go to a park, mall, theme park, etc.
Some place where there's going to be alot of people, and alot of benches....
See if you can find yourself a stranger, sitting alone at a bench or picnic table, sit down next to them and start talking to them. What you say to them is entirely up to you, but see if you can really invade their space....maybe put your arm up behind them, sit too close to them, whatever it takes.
See just how long they can handle the invasion of space, and how uncomfortable you can make them.