Make your own kebabs? Have vegetables and meat ready, ppl can put their own ingredients on their skewers and cook on the hot plate?

Baked potato - have the potatoes cooked, people top them with their own I ingredients (you can have have mince, sour cream, bacon, cheese, shallots etc to chose from)

The corn is a great idea PZ. When camping we actually wrap our corn in foil, and cook on the coals. You can squirt a bit of BBQ sauce and honey in some of them for a different flavor. A great side dish