I find that these bottles, which come in lots of sizes, are great for many purposes while backpacking. I have 12 oz ones, 4 oz ones, 2 oz ones, squat ones, tall ones, and the application I most use them for is fuel for my alcohol stove. If you're going out for a weekend, the 4 oz bottle takes up little space in your pack, weighs relatively little. I usually take a piece of wire and make the opening a little wider so the fuel comes out easier.
Obviously they can be used for putting solution in. You can repackage in a small one, some olive oil for cooking as well. Vinegar too.
What can you guys think of to use these for?
