I have several magic tricks that are suited to the bar:
Static Cigarette:
Rub the cigarette on your hand to 'create static electricity'. The trick is to blow slightly in front of the cigarette if you wish it to go away from you, following your hand. If you wish it to come towards you, cup your hand slightly and blow on your hand while bringing it towards you on the table. The hand will reflect the air onto the cigarette which will come towards you. The Audience will be looking at the cigarette rather than you blowing.
Matchbox Scam:
Ask someone to lend you $20 to put in an empty matchbox, you then also put $20 in. (You must point out the fact that you have also put in $20) Say to them that you will sell them the matchbox for $30. Believing that they are in for a bargain (spending $30 to buy a $40 matchbox). But the trick is that because they already have put in $20 they are in fact losing $10. (In total they have spent $50 for a $40 matchbox, and you get $30 instead of the $20 you started with.
Unless you want a punch in the face, I wouldn't run away
Just sit there and watch their face for a few seconds, until they realize. Coin/Cup trick:
Place a coin under a cup and say “I can get the coin without touching the cup." Do some acting and grab a coin (a different one) from under the table, then show them. Someone will say you cheated and lift up the glass. At this point, grab the coin.
Finally say: "I told you I could get the coin without touching the glass"