The iStraw is a lightweight polycarbonate straw that uses filtration technology to filter your water. As you can see, it is fairly small and so makes it perfect for your next trip up the Amazon, or any other country for that matter.
The manufacturers claim:
Portable: iStraw is Compact, light-weight and simple to use, an essential companion for all travelers.
Clean: Unlike water purification tablets, leaves no aftertaste.
Safe: iStraw is used for help in protection against waterborne bacteria and protozoa that are present in the drinking water of many countries.
Secure: Reduces up to 99.99999% of all waterborne bacteria, including Giardia and Cryptosporidium.
Rechargeable: Reusable - filters up to 500 liters of water.
The website also shows the following facts:
More than 50% of travelers report some kind sickness when traveling
Around 40% of travelers report Diarrhea
Nearly 18% of travelers lose at least 1 day of their trip to illness
Almost 4% losing 4 days or more to illness