This is a good start, but I would like to see more real world experience on 1) How will this benefit w.r.t replacing or using alongside Sessions (HttpSession in java for example) 2) Size limits - 5mb and 1mb for IE7, storages different per scheme/domains 3) Data Security
The size limits are more complicated, because strings get stored as utf16, so that 5 mb is a lot less in practice. Also, on ie7, you have to fall back to userData whose capacity depends on the security zone your app runs in, and can get as low as 64 kb.
I use it to replace cookies for storing settings that don't need to get sent to the server on every request. The collapsed state of a sidebar for example.
