Remy Sharp introduces you to web storage in HTML5

From his 24 Ways piece, Breaking Out The Edges of The Browser:

The Web Storage API is basically cookies on steroids, a unhealthy dosage of steroids. Cookies are always a pain to work with. First of all you have the problem of setting, changing and deleting them. Typically solved by Googling and blindly relying on PPK’s solution. If that wasn’t enough, there’s the 4Kb limit that some of you have hit when you really don’t want to.

The Web Storage API gets around all of the hoops you have to jump through with cookies. Storage supports around 5Mb of data per domain (the spec’s recommendation, but it’s open to the browsers to implement anything they like) and splits in to two types of storage objects:

Sharp discusses the different kinds of storage available in HTML5, plus browser support and fall-backs (such as Flash’s Local Storage Objects), and how to make an offline app.

And after you’re done reading about the Web Storage API, install the BetterPrivacy extension for Firefox which protects your privacy by letting you manage DOM Storage and Local Storage Objects.