What are the performance implications of waiting for callbacks to finish?

I have been programming with Node.js for a little while, and I have found myself becoming increasingly annoyed with the need to chain callbacks. For example, when you need multiple models from a database as shown:

Person.findOne({ 'name.last': 'Ghost' }, 'name occupation', function (err, person) {
    Schedule.findOne({'person_id': person.id }, 'events', function(err, schedule) {
        ...
    }
})

I am looking for solutions to this problem. One idea I had was to do something like this:

function() {
    var p;
    var s;
    var done = false;

    Person.findOne(..., ..., function(err, person) {
        p = person;
        done = true;
    });

    while(!done){}
    done = false;

    Schedule.findOne(..., ..., function(err, schedule) {
        s = schedule;
        done = true;
    });

    while(!done){}
    done = false;

    // ...
}

If I do my queries like this, what are the performance implications? I'm also open to other ideas for solving this problem.