I fold mine with the stem toward the center, much as ollo ollo describes. I take two rubber bands (made from old tubes I've cut up) and wrap around both ends. With presta valves, it's important to keep the valve open when you do this, or you never get all of the air out. Then I put it in a small zip-lock sandwich bag with a bit of baby powder (talc). After which it goes into the saddle bag. BTW, I keep pocket change, tire levers, patch kit, etc. all in their own zip lock bags. They weigh next to nothing, and it just makes keeping things organized easier.