I used some of my mutant zucchini last night to make this tasty side dish. Here's what I did:
Slice a zucchini into 1/2 inch slices (or a little thinner). Marinate them in Italian dressing for a couple of hours. Heat your grill to medium-high heat. Place the slices on the grill, cover and cook for about 4 minutes. After 4 minutes, turn them over and grill for 4 more minutes. Keep rotating every couple of minutes until they have nice, brown grill marks and are soft without being mushy. Season with salt and pepper if desired.