Do you live in the Sahara desert?

A popular ride out here is the North Cascades Highway; I'm guessing it's the ride Carbonfiberboy was commenting about not having enough water on. For about 50 miles with maybe 6,000' vert, there are no stores, no water fountains, no potable water of any kind. But there's a creek every mile. Most of the ride is through the desert, the creeks drain high glaciers and snowfields. CFboy suffered needlessly when he ran out of water in the hot(ter than he's used to) sun; this is a simple, light, cheap way to have avoided it.

That's a Sawyer Mini water filter, they run $15 to $25, weigh 2 ounces, and it's smaller than a spare tube.