Here's a very cool (and smart) tool that Nokia have created: a banner generator for your Marketplace apps.
Need a quick way to advertise your app via web banners or perhaps your website? Hop over to Nokia's generator, enter in your App URL and away you go. The system will pull in your app's info and then allow you to customize how the banner looks. You can choose which Nokia Windows Phone to display, which Tiles to show and more.
Cost? Free. Of course, Nokia gets their phone shown off now every time you advertise your app--one hand washes the other, right? Regardless, we think it's a great idea and looks snazzy.
Try it right here: http://snac.nokia.com/2/omt