It seems like every day there is another story in the news about water contamination. People getting sick from eating lettuce and salad vegetables because the water they were washed in is contaminated. Imagine you take your family on a weekend backpacking trip in one of our national parks and you are using a stream for water - are you sure it's free of bacteria? There are many portable ways to filter water. Some are designed for use in the outdoors and others are designed as precautionary measures against terrorism. Whatever the use, they are inexpensive ways to protect yourself when you're not sure of the safety of the water you are about to drink.