My wife and I had planned to make this last weekend, but things got out of hand (involving an emergency visit to the doctor for my 2 year old chowpup - he is fine though)
Anyhow, my wife did the Alton's leg of lamb recipe from the episode "Silence of the Lamb", and despite the fact that grilling and BBQ are generally my domain, she did a GREAT job.
It came out very juicy, tasty, and tender, though puling it off at 135 like he suggested, it got a bit more done than we had desired. Still, very juicy. The flavors of the mint, garlic, and mustard paste melded well with the lamb and the charcoal cooking process.
Even our little chow pup loved it, his first time having lamb (my wife is a bit non adventurous with non-standard meats, as she calls them ;) )
Can't wait to try it again sometime.