Originally Posted by
Retro Grouch
I don't often do this but I'm going to say "Bike Shop".
They'll be able to get the chain out and readjust the front derailleur so that it doesn't happen again in probably less time than you've spent reading this thread.
I agree that a good bike shop might be the easiest way to get this done... but it will be cheaper to buy the $10 crank puller tool and carefully adjust the shifting yourself to make sure it doesn't happen again.