If you're looking for a unique way to serve your next Caesar salad, slice several heads of romaine lettuce (organic is preferable) lengthwise in two, brush with olive oil, and place on the grill for several minutes on each side.
Note: Grill temperatures can vary significantly, so monitor your lettuce carefully. The below lettuce I grilled was put on a relatively cool grill which had been burning for at least an hour. If you're placing lettuce on a hotter grill, it will char much more quickly.