Some of the beach SUCKS. We stayed in Nags Head one year and the beach was rocky. Lotta little rocks.The nice thing about OBX is the beach town feel. The beaches are much sandier than SOMD beaches, without as many rocks. Waves are better, too.
I go every August with a group of people -- we rent a nice house for a week, everyone has their own room, and it's a lot of fun. Walking distance to the beach, awesome seafood restaurants, and it's just nice to "get away".
Go out at night and try to catch a bunch of the ghost crabs. Wait until someone is taking a shower and toss them in. Or put one in your shorts and walk up to a stranger and say "I think I've got the crabs" and pull it out.Bury someone in the sand with only their head showing, put seaweed over the top of their head. Then put a bucket over it (leave a gap for air) Then ask some kid who just arrived and hasn't seen you digging to please bring you the bucket. Video tape results.
Buy a cheap kite. Get it up as far as you can in an offshore breeze and cut the string. The string will drag in the surf and you can watch it head for the open sea.