I must be one of the biggest fans of WaterField Designs, a San Francisco designer and manufacturer of custom laptop sleeves, bags and device-specific cases. On my recent press trip to Germany and Italy, I used continuously the iPhone Camera Bag that I have reviewed previously. It managed to carry comfortably, two mobile devices, glasses and some cash. The trip I was on was extremely energetic with helicopter rides, boat trips and fast street photography in Sorrento. This bag coped admirably and now WaterField are debutting another very useful bag, which we hope to thoroughly review soon. It’s the Sutter Tech Sling bag, a sophisticated one-strap backpack in two sizes,…