Have you looked at this (use iframes and postMessage). http://stackoverflow.com/questions/4026479/use-localstorage-across-subdomains http://stackoverflow.com/q

Have you looked at this (use iframes and postMessage). http://stackoverflow.com/questions/4026479/use-localstorage-across-subdomains http://stackoverflow.com/questions/4026479/use-localstorage-... I haven't used it myself but am planning to for a project I am working on now.