Implement a 3¢ tax on plastic shopping bags provided by grocery stores and other commercial shopping venues.
This provides two major benefits:
1) Reducing the number of plastic bags that end up in our landfills, promoting the use of re-usable bags for shopping.
2) Provide a small source of additional tax revenue from the portion of the population unwilling to take simple steps to help our environment.
A simple, conservative scenario:
If 20% of the 114.8 million households in the US use 3 plastic shopping bags per week this would yield $107 billion in tax revenue/year (~1.8% of the federal budgetary expenditures). For around $3 any family could avoid this $4.68 in tax/year that this represents.