How to create a live bootable USB on a Mac to install Linux on a PC

From http://www.webupd8.org/2009/04/4-ways-to-create-bootable-live-usb.html

Using Diskutil (Mac OS X only)

1. Download the desired .img file
2. Open a Terminal (under Utilities)
3. Run diskutil list to get the current list of devices 
4. Insert your flash media
5. Run diskutil list again and determine the device node assigned to your flash media (e.g. /dev/disk2) 
6. Run diskutil unmountDisk /dev/diskN 
7. Execute sudo dd if=/path/to/downloaded.img of=/dev/diskN bs=1m 
8. Run diskutil eject /dev/diskN and remove your flash media when the command completes 
9. Insert the USB into the PC
10. Enter the BIOS setup in your PC
11. Set the USB to boot first
12. Reboot the computer
13. Install Linux