LocalStorage is a project mainly written in JavaScript, it's free.
Simple cross browser wrapper around localStorage API. Serializes objects to store as strings an parses them back on read. Works with IE6+, FF3+, Chrome etc.
This is a PrototypeJS powered abstraction of the localStorage API which provides backwards compatibility with IE6 & 7.
I've also started a jQuery port (included) but it's currently incomplete.
Testing has so far been VERY limited so use at your own risk!