$1 million

[wingywoof]

A question came up yesterday while talking to some friends in the garage

Comments

[ravenworks]

"But, officer, I was only changing my currency into one that would be easier to transport!"

[wingywoof]

You know you can't take more than $10k out of the U.S. without prior approval, right? A problem we all have to deal with so often. :P

[moonfires]

You don't need approval, you just need to file a form 105 if you're carrying 10k or more worth of bearer instruments.
http://www.cbp.gov/linkhandler/cgov/newsroom/publications/travel/currency_rpt_flyer/currency_reporting.ctt/currency_reporting.pdf