IStraw is a polycarbonate straw with a special membrane which clean you water. Very useful for travellers.
iStraw fitted a membrane which uses micro)filtration technology to clean water. It reduces up to 99,99999% of all bacteria, including Giardia and Cryptosporidium. If used properly, iStraw can filter up to 500 litres of water.
iStraw is available online for $49.99 from ThinkGeek.