index.js

function doClickMenu(evt){
  alert(evt.source.title);
}

// we need to do some things to the Window once it is properly instanciated, so we add an event listener to its OPEN event
$.win.addEventListener('open',function(){
	var actionBar = $.win.activity.actionBar; // get a handle to the action bar
	actionBar.title='My App'; // change the App Title
	actionBar.displayHomeAsUp=true; // Show the "angle" pointing back
	actionBar.onHomeIconItemSelected = function() { // what to do when the "home" icon is pressed
		Ti.API.info("Home icon clicked!");
    };	
})

// now open the window.  The event listener will fire right after this
$.win.open();

index.tss

"Window": {
  backgroundColor: "#fff"
},
"Label": {
	width: Ti.UI.SIZE,
	height: Ti.UI.SIZE,
	color: "#000",
	font: {
		fontSize: 20,
		fontFamily: 'Helvetica Neue'
	},
	textAlign: 'center'
},
"MenuItem": { // this tells the menu to be part of the actionbar if there's room.  Otherwise the options will be available by pressing the hardware menu button
	showAsAction: Ti.Android.SHOW_AS_ACTION_IF_ROOM,
},
'#menu1': {
	icon: 'images/action_about.png',
	title: 'About'
},
'#menu2': {
	icon: 'images/action_settings.png',
	title: 'Settings'
},
'#menu3': {
	icon: 'images/action_about.png',
	title: 'About'
},
'#menu4': {
	icon: 'images/action_settings.png',
	title: 'Settings'
},
'#menu5': {
	icon: 'images/action_about.png',
	title: 'About'
},
'#menu6': {
	icon: 'images/action_settings.png',
	title: 'Settings'
}

index.xml

<Alloy>
  <TabGroup id="win">
		<Tab title="Tab 1" icon="KS_nav_ui.png">
			<Window title="Tab 1">
				<Label>I am Window 1</Label>
        <!-- this menu is styled in such a way that it becomes part of the ActionBar.  See the TSS file -->
				<Menu id="menu" platform="android">
					<MenuItem id="menu1" onClick="doClickMenu" />
					<MenuItem id="menu2" onClick="doClickMenu" />
					<MenuItem id="menu3" onClick="doClickMenu" />
					<MenuItem id="menu4" onClick="doClickMenu" />
					<MenuItem id="menu5" onClick="doClickMenu" />
					<MenuItem id="menu6" onClick="doClickMenu" />
				</Menu>
			</Window>
		</Tab>
		<Tab title="Tab 2" icon="KS_nav_views.png">
			<Window title="Tab 2">
				<Label>I am Window 2</Label>
			</Window>
		</Tab>
	</TabGroup>
</Alloy>

tiapp.xml

<!-- you need to add this to your tiapp.xml -->
<android xmlns:android="http://schemas.android.com/apk/res/android">
	<tool-api-level>14</tool-api-level>
	<manifest>
		<application android:theme="@android:style/Theme.Holo.Light"></application>
		<!-- You could also use @android:style/Theme.Holo -->
	</manifest>
</android>

version 2.index.tss

// this version demonstrates how to specify which menu options you want to always appear on the menu bar
// and which you want to display as additional menu items
"Window": {
  backgroundColor: "#fff"
},
"Label": {
	width: Ti.UI.SIZE,
	height: Ti.UI.SIZE,
	color: "#000",
	font: {
		fontSize: 20,
		fontFamily: 'Helvetica Neue'
	},
	textAlign: 'center'
},
'#menu1': {
	icon: 'images/action_about.png',
	title: 'About',
	showAsAction: Ti.Android.SHOW_AS_ACTION_ALWAYS
},
'#menu2': {
	icon: 'images/action_settings.png',
	title: 'Menu',
	showAsAction: Ti.Android.SHOW_AS_ACTION_ALWAYS
},
'#menu3': {
	icon: 'images/action_about.png',
	title: 'About',
	showAsAction: Ti.Android.SHOW_AS_ACTION_NEVER
},
'#menu4': {
	icon: 'images/action_settings.png',
	title: 'Settings',
	showAsAction: Ti.Android.SHOW_AS_ACTION_NEVER
},
'#menu5': {
	icon: 'images/action_about.png',
	title: 'About',
	showAsAction: Ti.Android.SHOW_AS_ACTION_NEVER
},
'#menu6': {
	icon: 'images/action_settings.png',
	title: 'Settings',
	showAsAction: Ti.Android.SHOW_AS_ACTION_NEVER
}

version2.index.js

// this version demonstrates how to provide a "software" way of invoking the menu button.  This is until 
// Ti supports the MenuInflater
function doClickMenu(evt) {
  switch(evt.source.title){
		case "Menu": // in real life you probably wouldn't want to use the text of the menu option as your condition
			var actionBar = $.win.activity;
			actionBar.openOptionsMenu();
			break;
		default:
			alert(evt.source.title);	
	}
}

// we need to do some things to the Window once it is properly instanciated, so we add an event listener to its OPEN event
$.win.addEventListener('open', function() {
	var actionBar = $.win.activity.actionBar;
	// get a handle to the action bar
	actionBar.title = 'My App';
	// change the App Title
	actionBar.displayHomeAsUp = true;
	// Show the "angle" pointing back
	actionBar.onHomeIconItemSelected = function() {// what to do when the "home" icon is pressed
		Ti.API.info("Home icon clicked!");
	};
})
// now open the window. The event listener will fire right after this
$.win.open();