1. A system to enable a mobile device to use physical storage of another device for social caching, the system, comprising: a local proxy on the mobile device which detects or receives a response to a request to a content source; wherein, the local proxy wirelessly accesses the physical storage of another device via a wireless network to cache the response or content for the mobile device; wherein, responsive to subsequent requests at the mobile device which would be satisfied by the content or the response, the physical storage of the other device is further accessed via the wireless network to access the cache to satisfy the request at the mobile device; wherein, the physical storage of the other device is accessed in response to detecting commonalities between the mobile device and the other device; wherein, the commonalities include common interests in users of the mobile device and the other device; wherein the system further comprises a proxy server wirelessly coupled to communicate with the local proxy, wherein, the proxy server monitors the content source to determine when the response cached is no longer valid; wherein, the local proxy notifies a remote proxy when the response is cached; and wherein, the remote proxy notifies the local proxy on the mobile device when the response is no longer valid.