The Ubuntu 11.04 Natty Narwhal countdown banners contest hasn't started yet, but if you can't wait, you can use some cool banners provided by picomol.de. And if you're really impatient, you can go further and use a beautiful Ubuntu 11.10 Oneiric Ocelot countdown banner provided by the same website.
The banners use an image that's automatically updated so it can be inserted on any website (including wordpress.com, etc.). And what's even cooler is that the banners come in various sizes - you can see the Ubuntu 11.04 banners in action below:
If you're really really impatient, you can also use an Ubuntu 11.10 Oneiric Ocelot countdown banner which look awesome - and just like the Ubuntu 11.04 countdown banners, come in multiple sizes:
Want to use them on your site/blog? Get the code from here: Ubuntu 11.04 Natty Narwhal | Ubuntu 11.10 Oneiric Ocelot. The website is in German but all you have to do is click the "Anzeigen" link under a banner to get the code. If needed, use Google Translate.
Thanks to Valentin for the tip!