I also did update my BIOS using my USB flash drive...first of all, go to asus's website and download the newest bios version (1301 is the newest, link: http://support.asus.com/download/download.aspx?SLanguage=en-us&model=Striker Extreme). Move it to your flash drive. I suggest saving it to the root of the drive to make it easier to find.
Keep your flash drive plugged in!!
Now, restart and boot into BIOS. (Hit DEL at logo screen)
Go to: Tools >> Asus EZ Flash 2
Wait a few seconds.
Select your USB drive, and navigate to your updated BIOS file ("1301"), and then simply FLASH it!
Warning: make sure you do not turn off the computer or unplug your USB device until the procedure is fully complete!!