How to Grill steaks and tell when they're done

Over a hot grill, steaks will cook quickly, going from very soft (very rare) to somewhat soft with a bit of a spring (medium) to quite firm (well done). Steve Johnson, chef-owner of The Blue Room, recommends touching the steaks often and cutting into them when you think they're done, erring on the side of under-cooking since you can always cook the steaks longer, if necessary. In this video he demonstrates the how to grill steak and tell what stage it's cooked to.