1. One or more computer-readable storage mediums storing one or more sequences of instructions for transferring a file using a virtualized application, which when executed by one or more processors, cause: executing the virtualized application within a virtual machine running on a physical machine; upon the virtualized application receiving an instruction to download one or more files stored external to the physical machine, the virtualized application displaying an interface which enables at least a portion of a file system, maintained by a host operating system executing on the physical machine, to be browsed while preventing files stored within the virtual machine to be browsed; and upon the virtualized application receiving input identifying a target location within said file system, the virtualized application storing said one or more files at said target location.