So far, generally one photo ID is enough for travel, Passport will ALWAYS work, and in a lot of cases a Drivers License will (for now).
For other things, well, opened a new bank account for DS and they said federal law requires them to check 2 photo ID's for that since September 11th. . Actually, all I was doing was taking my name off DS's account because he just turned 18.
And we aren't talking about a lot of cash here, just $500.