This is actually pretty easy to do on your computer.
I used to work for a company that makes a product called "Cleaner" (
http://www4.discreet.com/cleanerxl/). You can convert PAL into NTSC or the other way around for that matter.
In many cases, software that can do this comes bundled with your computer.
Once you have it has a file, you can either burn it to a DVD or you can simply connect the video out from your video card to a VCR (a US VCR) and record it in NTSC for use back home.
Good Luck