Bankrate's Investing Blog has a short review
of Certificate of Deposit Account Registry Service (CDARS).
Two basic points that were mentioned:
1. CDARS make it easy to keep large deposits (up to $50M) FDIC insured.
2. You pay the price for that convenience with lower deposit rates
I reviewed CDARS rates from three banks in this post from last month
and compared those to what you can get at DollarSavingsDirect. They can spread your deposits across 5 of their separately chartered banks.