Such a simple idea for those times when you're stuck somewhere with your digital camera but no regular tripod: the Bottle Cap Tripod. With a standard screw connector at one end, the other end fits any normal water bottle, turning it into an impromptu camera stand. I wouldn't feel particularly confident attaching anything much bigger than a light, compact camera to it, even if the bottle was filled with liquid, but it could solve some problems when you just have to get that steady shot...