Former stamping grounds of some of history's most famous seafarers, the Virgin Islands are now invaded by thousands of visitors who arrive daily by cruise ship and plane from Miami and Puerto Rico. These green, hilly islands, some governed by the United States and some by Great Britain, number about 100 in all. Most are tiny and virtually uninhabited, except for a few birds or an adventurous boating party stopping off for a little snorkeling or swimming. For the ultimate tropical getaway, it's possible to rent an entire island for yourself.