Another method of cooking corn on the cob on a grill is with tinfoil. You don't have to deal with messy burn husks when you are getting ready to eat.
Take 6 ears of corn and remove the husks and silk. Take 2 large sheets of tinfoil and place the corn on the shiny side (conducts the heat better). You can wrap them individually as well for convenient serving.
Add 3-4 ice cubes, some slices of butter, and a dusting of salt and garlic salt on the ears of corn. Wrap it up good so the water doesn't leak out and place on the grill.
Cook for 15-20 minutes at medium heat.
Careful removing the package as it will be hot and any water that hasn't turned to steam will be boiling hot.
Also check out the recipe for grilled corn on the cob - in the husks.
Here is a YouTube video that goes over cooking corn on the cob on the grill in tinfoil.
Enjoy - this is an awesome addition to any BBQ.