The Cyber-shot family just keeps growing and growing, with its latest litter focused on keeping slim and staying active. The quartet's most rugged machine, the $330 16.2 megapixel DSC-TX20, promises to be tough as nails by tolerating water up to 16 feet under, bouncing back from five foot falls and braving freezing tundras as cold as 14 degrees Fahrenheit. The $350 DSC-TX66, on the other hand, forgoes the armor in favor of a 18.2 megapixel sensor, a 3.3-inch "Xtra Fine" OLED touc
