For some bored downtown workerbees, flattening coins on the F-Market track is a shiny way to pass the time. Take, for example, Matthew Knudsen, who pressed these beauties just the other day. SFist asked Knudsen to tell us how he did it. "I work at an ad agency across from the F, and walk over the tracks everyday and decided to put some coins on the line and see if they'd squash, like on railroad tracks," he explained. "After a few cars knocking them off, I got a train to nail two of them... They sort of jump off when the train hits them, and flattens them right out."

Should the public start doing this em masse while lollygagging near an aboveground Muni line. Probably not. SF MTA spokesperson Paul Rose warns SFist, "Because of the inherent danger, placing pennies on a working rail in the middle of vehicular traffic is something we cannot suggest."