Linux
WARNING, the following instructions will destroy any existing data on your USB stick.
Determine what device your USB is. With your USB plugged in run:
sudo ls -l /dev/disk/by-id/*usb*
This should produce output along the lines of:
lrwxrwxrwx 1 root root 9 2010-03-15 22:54 /dev/disk/by-id/usb-_USB_DISK_2.0_077508380189-0:0 -> ../../sdb
lrwxrwxrwx 1 root root 10 2010-03-15 22:54 /dev/disk/by-id/usb-_USB_DISK_2.0_077508380189-0:0-part1 -> ../../sdb1
In this example output, the USB device is sdb
Now cd to where your *.iso is
cd ~/downloads
Example
sudo dd if=filename.iso of=/dev/usbdevice bs=4M; sync
lets say the iso is named mini.iso and your USB device is sdb
Example
sudo dd if=mini.iso of=/dev/sdb bs=4M; sync
NOTE – Be sure to understand that there is never a trailing number on the end of your /dev/sdx USB device