I just came across this Chicago story from earlier this week about a bank robber who was caught thanks to the quick thinking of a bike messenger.

WBBM radio reported: 

The robber, armed with a butter knife, is suspected of walking into the North Community Bank, 2800 N Western Ave. and threatening a teller. The suspect allegedly grabbed money from the teller, who was counting it, and fled the bank by jumping into a cab, police said.

A bicycle messenger who saw what was going on began following the cab, which was weaving in and out of traffic. The messenger was able to use a cell phone to call authorities and direct police to where the suspect was, police said.

Nice to see a bike messenger in the news for being a hero instead of a complaints about red light running.