//your object
 var o = {
     foo:"bar",
     arr:[1,2,3],
     subo: {
         foo2:"bar2"
     }
 };

//called with every property and it's value
function process(key,value) {
    log(key + " : "+value);
}

function traverse(o,func) {
    for (i in o) {
        func.apply(this,[i,o[i]]);
        if (typeof(o[i])=="object") {
            //going on step down in the object tree!!
            traverse(o[i],func);
        }
}

//that's all... no magic, no bloated framework
traverse(o,process);




function traverse(jsonObj) {
    if( typeof jsonObj == "object" ) {
        $.each(jsonObj, function(k,v) {
            // k is either an array index or object key
            traverse(v);
        }
    }
    else {
        // jsonOb is a number or string
    }
}