Just returned from 2-week vacation in Nantucket, sharing the following thoughts:
1. Oran Mor was overrated for the price. Black Eyed Susan's has better food and better value (it's byob).
2. Downyflake still has the best breakfast on the island.
3. Fog Island Cafe is a good bet for lunch.
4. For takeout, try the thai menu at fahey and fromagerie.
5. Sfoglia is quite good (esp. the fruit tart desserts w/ ice cream) and seemed child-friendly; bring your own high chair or booster seat.
6. Cookies (esp. oatmeal raisin) at something natural are very good.