I've looked everywhere for lightweight rain protection that works and finally found it in the Montane Minimus Smock. At only 5 ounces it hides in a pack and offers serious protection when you need it.
Unlike some of the flimsy jackets on the market, the Minimus Smock takes the abuse in stride without showing wear. I've had the jacket through the mountains of Colorado during the shoulder seasons (leaving the full Gore-Tex at home) and have traveled throughout Asia in the rainy season. The only time I've been wet is from perspiration. It's a breathable jacket, but rain and 100 degree fahrenheit temps aren't a good mix no matter what you're wearing.
Links
Montane Minimus Smock: http://goo.gl/n9xNDD
More gear reviews: http://goo.gl/0x4zz
