june 30th is the deadline, and american citizens with a total of over $10,000 in foreign accounts must notify the IRS by that date.
it's definitely annoying, but unlike other IRS forms this one is easy enough to fill out....
acct #s
ammounts (in $)
names and addresses of the banks
FAQs Regarding Report of Foreign Bank and Financial Accounts (FBAR)
http://www.irs.gov/pub/irs-pdf/f90221.pdf