Pentax Optio W10
Neither rain, nor sleet, nor snow, nor sand, nor mud, nor dust will stop the 6-megapixel Pentax Optio W10. This postal-worker-worthy camera is specially sealed to prevent damage from the elements, completely submersible in water to a depth of 4.9 feet for up to 30 minutes, and impenetrable to dust particles as fine as talcum powder. Even if you don't plan on taking it into the drink or the desert, the Optio W10's design makes it virtually immune to the wet, nasty weather that could kill other cameras.
The Pentax Optio W10's compact plastic body weighs about 5.5 ounces, and at less than an inch thick, it can slip easily into your pocket; the modest 3X, 38mm-to-114mm lens zooms entirely into the body. It lacks an optical viewfinder, so you'll have to depend on its large, 2.5-inch LCD for composing your shots. The somewhat dim display is great for underwater shooting but can be difficult to view in low light. The screen barely gains up, and the LCD-brighten feature doesn't help much.
The camera's body feels relatively comfortable to hold, and it even has a space on the back to rest your thumb while shooting. Also on the back is a zoom lever, a playback button, a menu button, a special green mode/delete button (more about that later), and a five-way-plus-OK pad to navigate the menu and to control settings such as flash, self-timer, and macro.
The tripod mount on the underside of the camera doesn't line up with the lens, but at least it's made of metal instead of strip-prone plastic. The battery/memory-card cover locks in place so that the compartment doesn't get soaked when the camera is submerged--but make sure it's secure before you take it for a dip.