BankersBox - a Redis-like API for localStorage
twilio.com
twilio.com
These look like awesome and useful abstractions for a lot of things, I may use it for saving and loading games, for example. But I recommend caution if you're thinking about using localStorage to store a lot of entries.
It's not advisable to use it for a lot of data, especially if you actually need that data to stay around - it's better in situations where it's okay if the data goes away. You also need to be ready to handle over quota errors - e.g. in my lscache library, we kick out old data when that happens. I talked about that in a localStorage talk recently (http://client-side-storage.appspot.com/ - click "show notes").
You might want to use the Lawnchair library, as that can be used with both localStorage and IndexedDB, which can theoretically handle a lot more data with better performance.
I think people run into problems when they store megabytes instead of kilobytes. Localstorage is essentially cookie storage without the networking dependency. Treat it like that and it works well.
Many localStorage libraries fallback to older techniques (window.name, userData, etc). It looks like BankersBox has an adaptor interface, so if you wanted support in the older browsers, you could write an adaptor (check out Lawnchair/store.js to see how to use those older APIs).