Food poisoning sucks and it could even be from brushing your teeth so if in doubt get sealed bottled water. I really want to spend a few months travelling around South America get to see more of the countries and culture. I'd like to spend a few weeks in Tahiti rather than a few days

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Travel advice: watch out for roadside stalls in some third world countries they often don't wash out the glasses and you could get TB (if not vaccinated try and get some immunization before you travel, also hep B vaccine). If you can get hydrogen peroxide 30%, iodine, dressings if backpacking or surfing. Hydrogen peroxide just bubbles like crazy on reef cuts! Also a first aid kit. In cities I always keep my wallet as close to my body as possible, internal jacket pocket etc so I can feel it and it's not as obvious I'm a tourist with a bag or bum bag. Always watch out for pick-pockets/bag snatchers especially in crowded markets, trains etc. Try not to carry your passport around with you keep it at a secure location such as a hotel safety deposit or some such. Never leave your bags unlocked especially at an airport. Most important have fun.
I think you are over exaggerating the risks of food poisoning. I have spent over a year in third world countries and only had proper food poisoning twice (once of a pizza in Bolivia, and the other time was my fault as I left some dirty dishes out in the sun for a few days and then just washed them in tap water before eating off them in Thailand).
Anyway, I've spent about 5 months in South East Asia (Thailand, Laos, Cambodia, Vietnam and Singapore) and 7 months in the US and Latin America (Costa Rica, Nicaragua, Panama, Colombia, Peru, Bolivia, Chile and Argentina).
My favourite places were:
Thailand and Laos - amazing food and great people. I spent a few months teaching English there and loved it. Totally immersed myself in the culture. I love Laos too for similiar reasons but it is a bit more laid back.
Nicaragua - this one was a real surprise. It was a really beautiful country and it had hardly any tourists. Great jungles, cool cities and lots of volcanoes. The people were awesome too.
Colombia - beautiful women, cool people, great cities. The people of Colombia were the highlight for me, so warm and welcoming. In South America the people in general rock but Colombians were the best of a good bunch.
Peru - Ancient cultures, jungles, the andeas and deserts. Plus some of the best and most unique food in South America (plus the best coke).
Bolivia - only because of the time I spent in the salt flats and 5 days trekking and boating in the amazon.
Places I want to go:
A month long trip to India (and maybe Nepal) will probably be next in about a year.
I'd love to do a nice long trip up the east coast of Africa starting in South Africa and working my way up to Egypt and into the Middle East. That is a real pipe dream at the moment as it would coast like $15K+ and force me to quit my career - but hey we can all dream.
Love this thread - getting me all excited about travelling again.