No Cookies ? No Ajax ? No Server ? No Gears ? It's simple, JSTONE !
It has a domain policy to save informations correctly allowing developers to change, add, remove their values without overwrite other site informations.
JSTONE uses basically unsecure (atleast in my humil opinion) window.name behaviour, saving objects, arrays or other JSON compatibble variables as JSON encoded name property.
What should be JSTONE useful for?
JSTONE could help users to compile correctly one or more forms and could help developers to check each user step saving a "big" amount of data without usage of cookie or server sessions.
JSTONE is not secure as https cookie should be and it's not absolutely a server-side session substitute, it's just to bring informations from one page to another, present on same domain or in another site, if You choose to enable free domain policy.
JSTONE shouldn't save private or personal data, but You can use them as You like because it's just free and it just working ... how it should work, is part of your immagination :-)
Do You like JSTONE idea? :-)