Google AdWords now accepts Half Page 300×600 Display Network ads. Google AdSense announced yesterday that they have added a new 300×600 ad unit. This new size is available for Image, Animated and Flash ads.
When I visited the See Sample image sizes link the new size was mentioned but no sample has been provided, but we get the idea, it is a large piece of page real estate that is being taken up. The AdSense blog mentioned the addition of this new size was due to larger monitors, requests from publishers and the ability to allow advertisers larger space for they messaging to be some of the reasons behind the addition of this new larger ad unit.