To convert an object to a string, use
var json_text = JSON.stringify(your_object, null, 2);
To convert a JSON string to object, use
var your_object = JSON.parse(json_text);
It was recently recommended by John Resig:
...PLEASE start migrating your JSON-using applications over to Crockford's json2.js. It is fully compatible with the ECMAScript 5 specification and gracefully degrades if a native (faster!) implementation exists.
In fact, I just landed a change in jQuery yesterday that utilizes the JSON.parse method if it exists, now that it has been completely specified.
All modern browsers (and many older ones which aren't ancient) support the JSON object natively. The current version of Crockford's JSON library will only define
JSON.parse if they're not already defined, leaving any browser native implementation intact.