Like Tim said you need to think who's going to buy these photos, and why they would pay you the thousands of dollars it takes to live and travel on when they can get a subscription to a stock website where there are virtually limitless photos for significantly less than they would pay you.
The think with weddings is that you've got 1 chance to get it right so there will always be people prepared to pay a premium to ensure they get a pro and the moment is not lost, the same applies for a commercial shoot where they're getting models and all sorts of other stuff lines up for the day. Travel photography is a different ballgame altogether, there's no risk associated with purchasing cheap stock images because you can see exactly what you're buying before you part with your cash, and there will ALWAYS be thousands of amazingly talented amateur travel photographers happy to get paid next to nothing to see their photo in a magazine or ad.
I'm saying in 2010 it's borderline impossible to achieve what you're suggesting. Maybe you could carve a niche as a fine art artist and sell limited quantities of your images to cashed up art lovers, but it's not going to be easy.