A better idea

Ditch the penny and swap dollar bills for coins. I see several advantages:
1) Same number of coins overall - good for those cash drawers
2) Creates an actual incentive to use dollar coins instead of bills (i.e. no bills)
3) Makes for easier vending/parking meter use, etc

Of course, maybe we'll stop using cash entirely at some point, but probably not until Craigslist goes belly up!