One of my favorite traditions when going to a new island (actually they have all been new to me since I have never been to one island twice..yet!) is to bring back a bottle full of sand and I display samples of sand from all the islands I have been to in decorative jars on my kitchen window sill.
Take a guess...which of the 3 islands I have visited has the whitest sand??
(I have also been to the Bahamas but that was when I was younger and hadn't started my tradition yet :-))