The LifeStraw is a portable use water filter, with a cost of about five dollars ($US) per unit. It is capable of filtering about 185 gallons (700 litres) in its lifetime, and is easy to clean. It removes 99.9999% of waterborne bacteria, and more than 98% of waterborne viruses.
LifeStraw is not only easily affordable, it offers safe drinking water wherever the user is. This means that any person traveling can carry a lifestraw and have safe water to drink wherever they can locate water (although it does not make saline water potable). More can be found out about the LifeStraw here.