International Photo Awards Site.
So I was having trouble thinking of something to do for a class one day and I searched "commercial photographer awards" and this link came up. There is a great amount of work you can view from several years of winners from the International Photography Awards. To enter for 2008, you can upload digital images, I think $15 for one image and $30 for 2-5 in a series.
The image above is by Chris Frazer Smith and you can see it again on this page