U. S. Regulators shut two banks in California and two smaller banks in Georgia and South Dakota on Friday, boosting to 57 the number of federally FDIC insured banks to fail this year.

Here’s how to check if your bank is solvent, and if it’s FDIC insured.

The Federal Deposit Insurance Corp (FDIC) said the weekend bank closings affected:

Temecula Valley Bank, in Temecula, Calif., with $1.5 billion in assets and deposits of about $1.3 billion as of May 31.
Vineyard Bank, National Association, of Rancho Cucamonga, Calif. It had assets of $1.9 billion and $1.6 billion in deposits as of March 31.
First Piedmont Bank, based in Winder, Ga., which had about $115 million in assets and $109 million in deposits as of July 6.
BankFirst, based in Sioux Falls, S.D., with around $275 million in assets and $254 million in deposits as of April 30.

Customers can access their money over the weekend by check, teller machine or debit card, the FDIC said.

57 banks have been closed so far in 2009, compared with 25 in 2008 and only 3 in 2007. You can see the complete list of failed banks here at the FDIC web site, or type in your bank name here to check out what the FDIC says. Or check out the bank ratings at Bankrate.com.

Seattle-based lender Washington Mutual became the biggest bank to fail in U.S. history. It was closed in September while suffering from losses from bad mortgages and liquidity problems. In this case, WaMu was sold to JP Morgan Chase Bank.

What happens when the FDIC takes over a bank?

Government regulators generally close a bank on a Friday, and reopen it on Monday with new ownership. Usually another bank will buy the failed bank’s business, minus any problem loans and troubled assets. Regulators immediately turn the failed bank over to the FDIC, which works over the weekend to ensure an orderly transition, and the bank reopens with new ownership on Monday. Meanwhile, the old bank’s customers can conduct their business as usual, accessing accounts using ATMs, checks and debit cards as if nothing had happened. That access continues once the bank reopens, and at some point the new bank will issue new checks, cards, and so on.

If a solvent bank can’t be found to take over the failed one, however, it’s a different story. The FDIC will notify you that the bank is closing, and then your deposit accounts will be effectively shut down. It may take a few days before you get a check from the FDIC for your insured money. Remember that FDIC insurance is good up to $250,000.