gistfile1.js

var list = [ 1, 2, 3, 4, 5 ];
var loop_cb = (function () {
    // if the list is empty, we're finished.
    if (0 === list.length) { finished_cb(); }
    // get the next value from the list
    var next_value = list.shift();
    // start a DB transaction    
    db.transaction(function (tx) {
        // execute a SQL query
        tx.executeSql(
            "SELECT foo FROM bar WHERE baz=?", [ next_value ],
            function (rs) {
                // do something with the result set.
                // ...
                // perform the next loop iteration
                loop_cb(); 
            },
            function () {
                // something went wrong!
            }
        )
    });
});

var finished_cb = (function () {
    // all done with the above loop!
});

loop_cp(); // start the loop

// note that code past here continues to execute before the above loop has completed