Was at the foreign exchange today for the missus' US dollars and the woman behind the counter proclaimed that US customs officials are beginning to come down on people bringing too much cash into the country?

Seeing as my girlfriend was only buying $500 I thought this was a bit strange? Is there any truth to this or was she just talking b*ll*x?

She doesn't know what she is talking about.

You can bring as much money as you like into the US - the only requirement is that amounts over $10,000 have to be reported - no way is having $500 in cash on you going to be an issue.

That's exactly what I thought. A sales pitch gone bad because I effectively told her to poke her fancy debit card scheme where the elemenst will never get to it

md90565 is right. You can bring in up to 10k in cash or other financial instruments without declaring it, but over that you must declare it or it can be confiscated.