Wondering what the money limitations are for someone traveling to the USA? How much can be brought with them?

You can bring up to (but not including) $10,000 US without having to fill out a form. $10,000 and up, you need this form:
http://www.fincen.gov/fin105_cmir.pdf

You better have a good explanation for having so much money with you if asked by the customs officer if you plan on taking a lot.

No more than $10000.