SAN FRANCISCO—In some ways, the Bay Area's Occupy movement is a cheap imitation of the Wall Street version.

Camps are more like parties. There's hip-hop music blasting. The smell of pot smoke is noticeable, and on school days the Berkeley camp thins as students choose classes or sleeping in over conflict.

For all the faults, though, protesters in the Bay Area, especially Occupy San Francisco, have something their East Coast neighbors don't: a realistic plan aimed at the heart of banks. The idea could be expanded nationwide to send a message to a compromised Washington and the financial industry.

It's called a municipal bank. Simply put, it would transfer the City of San Francisco's bank accounts—about $2 billion now spread between such banks as Bank of America Corp. , UnionBanCal Corp. and Wells Fargo & Co . —into a public bank. That bank would use small local banks to lend to the community.

Backers of the plan aren't using a reckless approach. They're proposing a three- to five-year transition period and the relocation of just $500 million initially. It would be chartered as a credit union, member-owned and insured.