the easiest way for island hopping is to go with LIAT or Caribbean Star. I know that in 2002 Liat offerend something like three islands for about 100 US$.
The planes are smal (like a bus) and I was told that LIAT is the short form of 'Leave Island Any Time' but my expiriences are good. Nice stuff and quick flights between the islands. Martinique is beautiful - if you speak french! Grenada, St. Lucia and Barbados are nice and Union Island is a must if you love snokeling because it is right in front of the Tobago Keys (nothing to do with Tobago) where you can only go by boat and snorkeling is amazing. But - in the end - Tobago is the nicest!
Good luck and sorry to miss yo because I stay from Sept. 28th to October 12th.
Enjoy Tobago
Cheers











