As part of PopSci's "Future of the Environment" special, we commissioned a modern, eco-themed take on the classic videogame "Frogger." In our version, called "The Walker," players have to catch various forms of alternatively fueled vehicles to help them cross a busy highway and make it to school on time.

Photo buffs love SLRs because the optical viewfinder shows exactly what the camera sees. But sometimes a point-and-shoot is more convenient. Its LCD is great for framing awkward shots where you cant get your eyeball up to that little window, such as holding the camera high to shoot over a crowd or low to snap pets. Sonys new high-end cameras deliver the best of both worlds: an SLR with a fast, accurate digital-preview option.