WARNING!!

This code is outdated it is just here for Hysterical reasons, Please use the one on monotouch-bindings repo instead.

AlexTouch.GoogleAdMobAds

This is a MonoTouch Binding for Google's AdMob library Version 6.2.0

You just need to download the project, Open it with MonoDevelop, build project and add the resulting AlexTouch.GoogleAdMobAds.dll to your MonoTouch project (This DLL will be located in /AlexTouch.GoogleAdMobAds/bin/<DEBUG|RELEASE>/AlexTouch.GoogleAdMobAds.dll).

Once referenced in your MonoTouch project add the following using statement to your source file.

        using AlexTouch.GoogleAdMobAds;

Also it uses the c# events =) so Have Fun!!

        var ad = new GADBannerView(GADAdSizeCons.MediumRectangle,new PointF(0,0))
        {
            AdUnitID = "Use Your AdMob Id here",
            RootViewController = this //or your RootViewController  
        };

        ad.DidReceiveAd += delegate 
        {
            this.View.AddSubview(ad);
            Console.WriteLine("AD Received");
        };

        ad.DidFailToReceiveAdWithError += delegate(object sender, GADBannerViewDidFailWithErrorEventArgs e) {
            Console.WriteLine(e.Error);
        };

        ad.WillPresentScreen += delegate {
            Console.WriteLine("showing new screen");
        };

        ad.WillLeaveApplication += delegate {
            Console.WriteLine("I will leave application");
        };

        ad.WillDismissScreen += delegate {
            Console.WriteLine("Dismissing opened screen");
        };

        Console.Write("Requesting Ad");
        ad.LoadRequest(new GADRequest());

Also visit the official documentation of this API

http://code.google.com/mobile/ads/docs/ios/fundamentals.html
http://code.google.com/mobile/ads/docs/ios/intermediate.html
http://code.google.com/mobile/ads/docs/ios/advanced.html