since i've stayed 4 times a the hhi resort, most recently 10/12, i feel qualified to take this one.
1. rent bicycles and ride on the beaches, you can rent bikes for length of stay right from disney, they are big tire cruisers with locks, perfect for riding all over the island, follow the path from the resort, along the creek, under rte 278 and enter into palmetto dunes resort, and follow the signs for the disney beahc house, once on the beach turn right and ride west on the beach until you come to a beach access with a nice looking restrooms/shower,benches type area, that's the coligny circle access, you can get snacks in the shopping center, ride up to 278 and ride the bike path back to disney/shelter island. or go back along the beach depending on how strong the wind is
2. pay the $5 access fee to enter sea pines plantation, park at and take a walk on the trails of their nature preserve in the am, then go to harbortown and walk around, maybe have a lunch.
http://101thingshiltonhead.com/101-things/lay-of-the-land/4717
3. if you've never been to savannah before, it's worth the 40 mile drive and the parking to walk around the various squares and along the riverwalk, there's a lot of preserved buildings from as early as the 1700's.
http://www.visitsavannah.com/
4. have at least 1 meal at a restaurant called
http://www.hhbackyard.com/ ; the shrimp & grits is to die for
5. ride the bike paths and take lots of pictures
6. if you like seafood, eat at hudsons, great seafood. mailto:http://www.hudsonsonthedocks.com/
if i think of more, i'll add more posts/links