Go for it ChrisE, best way to do it is to get a round the world ticket you go one way around the world not coming back on yourself.
Best company to talk to is "Trailfinders" in London, they are pretty sharp with the "round the worlds" decide where you want to to, as you mentioned Asia, America etc, I would also take in parts of South America. Thjey have cool routings.
Hit me up on ICQ if you wantr anymore
117151486
