Working in South America for the last 11 years I drank tap water everywhere except Potosi in Bolivia, where the mining has led to contamination of the water table. Only ever seemed to get sick in Cuzco, Peru, and who can say, but that might have been more to do with too much poorly cooked "european style" food. Certainly wouldn't blame the Cuba Libres at Paddy's or Norton Rats Tavern!
On a trip from Senegal to Somalia this year we used a single Doulton ceramic water filter with a small caravan pump. One case of giardia (Uganda) in 9 months (don't think it came from our tanks) and we used some pretty rank sources in Angola with no ill effects, but I guess this is a bit bulky for a bike. We did have a couple of filter bottles ( Lifesaversystems.com) which you fill from wherever, and shake to filter. Worked really well for our cyclists, but much more hassle than filling their bottles from the support car. As I said though, it's not a big issue in SAm.
Last edited by mossproof; 6 Oct 2010 at 21:40.
Reason: more info