I just bought some pre-sliced London Broil (kosher and therefore pre-salted). I have never cooked it before, but understand that it can be tough and therefore should not be overcooked. A simple marinade for the barbecue would be terrific.
Most people have only tasted fresh grapefruit, and not everyone enjoys the tartness of it. Jenny Stewart of CHOW.com suggests broiling the citrus fruit with sugar to add a caramelized sweetness. And if you're adventurous, go crazy with any flavor combination you can think of—you might be surprised how well it works.