This article is from the Boats FAQ, by John F. Hughes with numerous contributions by others.
Some countries require a sailing license. Check with your
embassy. Many countries, like the US, do not.
Various rec.boaters have posted saying "I'm going to be in Country XXX
for two weeks and would love to sail with someone on such-and-such a
date," and have found themselves with a ride. The group's general
attitude towards this sort of thing seems to be "supportive."
In Australia, the Monash U. Sailing Club (or its president) can be reached
Peter Gustafsson ( email@example.com) offers to tell folks
about sailing in Sweden if they are interested.