How to issue touch and other gestures with appium in a hybrid app?

hybrid.js

"use strict";

var wd = require("wd"),
  should = require("should"),
	appURL = "http://appium.s3.amazonaws.com/WebViewApp6.0.app.zip";

// Instantiate a new browser sessoin
	var browser = wd.remote("localhost", 4723);

	// See whats going on
	browser.on('status', function(info) {
		console.log('\x1b[36m%s\x1b[0m', info);
	});

	browser.on('command', function(meth, path, data) {
		console.log(' > \x1b[33m%s\x1b[0m: %s', meth, path, data || '');
	});

	// Run the test
	browser
	.chain()
	.init({
		device: 'iPhone Simulator'
		, name: "Appium Hybrid App: with WD"
		, platform:'Mac 10.8'
		, app: appURL
		, version: ''
		, browserName: ''
	})
	.windowHandles(function(err, handles) {
		handles.length.should.be.above(0);
		browser.window(handles[0], function() {
			browser.elementById('i_am_an_id', function(err, el) {
				should.not.exist(err);
				el.text(function(err, text) {
					text.should.eql("I am a div");
					browser.elementById('submit', function(err, submit) {
						should.not.exist(err);
						should.exist(submit);
						// submit.click(function() { using click works
						// Q: What to put here for gestures on dom elements?
						var opts = { x: 0.5, y: 0.5, element: submit };
						browser.execute('mobile: tap', [ opts ], function(err) {
							should.not.exist(err);
							browser.execute("mobile: leaveWebView", function() {
								browser.quit();
							});
						});
					});
				});
			});
		});
	});