Take your key, put it between your middle finger and ring finger, make a fist, punch them in their eye.
Odds are you wont connect with their eye but will connect with their cheek or neck area.
Once a few years back.... I had a friend who had some nice rims.... he came to pick me up at the airport.... we went out to his car and a guy and one of his friends had his car jacked up and were working on their second wheel... we confronted them and got ready to brawl.... my friend got his tire out of the trunk and one guy ran to his car..... guy using jack took the rod to raise the jack and raised up like he was gonna swing at me... dude said "best not say s*** motherfucker" and walked towards me.... threw my Taco Bell cup at him and grabbed my keys.... shanked his ass on the side of his face... he dropped the pipe..... jumped in the car and took off..... we put the first tire back on...... and tightened up the one he was working on. Got a free tire jack out of it.... bad thing is they tried to pull the locks on his car and it had the ring on the paint scratched into it..... and i also lost my pepsi.