1. A virtual computing cloud comprising: a plurality of server grids operable to communicate with each other via a wide area network; each server grid having associated therewith a plurality of physical servers; each server grid having associated therewith a respective portion of computing resources; the plurality of server grids including a first server grid deployed at a first geographic location and a second server grid deployed at a second geographic location different than the first geographic location; virtual computing cloud resources, the virtual computing cloud resources including an aggregate of portions of resources associated with the first and second server grids; the virtual computing cloud being operable to run, at one or more of the plurality of server grids, a first instance of a distributed application implemented using at least one virtual appliance.