1. A public computing system, comprising: a plurality of computers to be used by patrons of a public computing infrastructure, wherein each of the plurality of computers includes a virtual machine monitor, each virtual machine monitor being associated with a plurality of base virtual machines images each representing a specific computing environment available to patrons of the public computing infrastructure; one or more servers coupled to the plurality of computers via a network connection, wherein the one or more servers store, for a predetermined time period, a single delta image for each base virtual machine image utilized by a particular patron of the public computing infrastructure, the delta image representing one or more changes made to a base virtual machine image by the patron and recorded as a differential update with respect to the base virtual machine image utilized by the patron, wherein storage of the delta image allows the system to maintain a virtual personal computing environment for the patron in subsequent sessions, wherein a snapshot of the patron's personal computing environment is saved at predetermined intervals during a session to enable the patron to retrieve the snapshot at a later time or session, wherein each of the plurality of base virtual machine images are stored separate from each corresponding delta image; wherein the virtual machine monitor to: (i) enable selection of one of the plurality of base virtual machine images by the patron and to launch the selected one of the plurality of base virtual machine images on one computer of the plurality of computers, (ii) retrieve the delta image corresponding to the patron and corresponding to the selected base virtual machine image from the one or more servers and modify the selected base virtual machine image of the one computer based on the retrieved delta image, and (iii) create a new delta image based on one or more changes made by the patron to the selected base virtual machine image upon a request by the patron to place the one computer in a suspended or powered-down state; and wherein, in response to the patron subsequently re-selecting the previously selected base virtual machine image, the virtual machine monitor places the re-selected base virtual machine image of the one computer in a state equal to the state of the base virtual machine image previously used by the patron based on the new delta image and the selected based virtual machine image.