I will keep adding to this, links that I find useful when travelling.
Don't trust other travellers to tell you where your might or might not catch malaria or other diseases, it's just not worth it. This site has good info, even telling you which anti malarials are most useful in each part:-
World Health Organisation (WHO) Internation Travel and Health Site
http://www.who.int/ith/en/index.html
Each Government has it's own travelers information website telling you how dangerous a country is. before you get too concerned about the dangers of a place like Colombia, be sure to check out what your local government says about someplace relatively safe, like England.
http://www.smarttraveler.gov.au/
If, like me, you are travelling from country to country you might want to post things home from time to time, but some countries have postal that is prohibitively expensive, and others are ok. So, if you are near to crossing the border you might decide to wait to the next country before you post the items home if the cost saving is worth it. I found a website that will help you make such decisions, as it mostly will link you to the website of the postal authority in the country requested.
http://www.postalrates.info/
A packing list of what to take backpacking for a trip like mine:
http://nomadali.blogspot.com/2011/02/backpackers-pack-list.html
