Today, hans notify me that there is a persistent storage solution in client-side in the form of jQuery plug-in called jStore.

Below is self-explanation：

A powerful plugin which gives jQuery the ability to utilize all current and upcoming Client-Side persistent storage solutions. jStore supports, not only a number of different storage engines (depending on the specific configurations of the user), but the ability to create and access multiple instances of each engine.

I spent some time to learn it and come to an example to share with you:

I think this plug-in is under heavy development now, because there are some obvious mistakes:
1. The API does't match with the code.
  jQuery.jStore.store('myKey'); has been changed to jQuery.store('myKey');
2. There is a mistake in the source (jStore.Flash.js):
  Line 10, 'return !!(njQuery.hasFlash('8.0.0'));', njQuery should be jQuery.
3. I try to set '$.jStore.defaults.engine = 'flash';', but there are some mistakes also.

Finally:
There are only two Engines that support all majior brousers(Firefox, IE6, IE7, IE8):
Flash and Gears.

 Here is the example.