Thanks Erin. You inspired me to dig around some more. I agree with the 540 calories estimate for a Big Mac. However, as a 240# male I will burn more calories than a svelte young lady! The "Daily Plate" website claims 331 calories for a 145# person picking up litter. Picking up litter seems analogous to picking up a penny and one that has rolled under a table would take about 8 seconds. With my super sized body I would easily burn 340 calories per hour picking up litter (pennies). That would be about 5.67 calories per minute. 8 seconds = 0.756 of a calorie. A Big Mac costs $3.57 (per Economist July 24, 2008 Big Mac index for USA) plus Cook County, IL sales tax (highest in nation!) comes to $3.93. Thus, 540 calories / 393¢ = 1.37 calories for each cent spent on a Big Mac.

Conclusion: picking up a penny burns about 75% of one calorie; each cent picked up can buy 1.37 calories worth of Big Mac. Thus, it can be easily seen that if you picked up 10 pennies in a similar fashion you would expend just 7.5 calories but you would have enough pennies to buy 13.7 calories!

Moral: NEVER PICK UP A PENNY AT MCDONALDS, YOU'LL JUST GET FATTER FASTER.

Well, housecleaning is probably the closest activity to picking up a penny, and that burns about 100 calories per hour. And a Big Mac is 540 calories. So you could pick up pennies for almost six hours straight before you burned off a Big Mac. I don't think you could buy anything at McDonald's that would be as few calories as you expend in picking up just one penny.