Peter Wayner takes a deep look at four cloud computing services: Amazon EC2, Google App Engine, GoGrid, and AppNexus, each of which simplifies your workload but forces you into a ‘ball-and-chain-computing’ routine you may not like. Although the services do let you pull CPU cycles from thin air when you need it, they can’t solve the deepest problems that make it hard for applications to scale gracefully, Wayner writes. Overall, Wayner finds the ‘clouds’ rife with potential but ‘far from clear winners over traditional shared Web hosting.’