gistfile1.js

    function complete(x,value) {
        var values = arguments.callee.values;
        values[x] = value;
        if (++arguments.callee.completed < 2) return;
        // do whatever with values
    }
    asyncOp("foo", function(err,data) { complete("foo",data); })
    asyncOp("bar", function(err,data) { complete("bar",data); })