Some of you may know about them. I didn't until recently and I have to say they are undoubtedly the champions of world travel on a Harley. They've traveled for 13 years on a 1994 Electraglide Classic, visiting 193 countries. Their website is here:
http://www.horizonsunlimited.com/forwood/
The FAQ's give a great overview. I'm just gobsmacked that they've done as much travel on as much dirt as they have. I'd love to meet them someday. What an inspiration!