Although, when I see a penny on the ground - I don't pick it up as a rule. I figure it's worth something, but not enough for the effort to bend over and pick it up - especially factoring in all the potential hazards of picking something up off the ground.
Pennies are actually worse than worthless! They cost 1.4 cents to produce and that cost is only getting higher! The federal government is actually looking into alternatives to copper at this point and may discontinue production of new pennies in the coming years.
cashmoneylife.com/2009/04/01/us-mint-cease-penny-production-in-2011/