Two current competitions...
Local Flavor: a 'local flavor' themed tote bag competition where 20% of the profits benefit Chez Panisse Foundation. The Chez Panisse Foundation works to give students the knowledge to build a sustainable future through their school curriculum and lunch program.
Create Your Own Hero: a t-shirt competition to create a modern day hero relevant to current times. 20% of profits benefit 826 National, a creative writing non-profit.
A site like this is great. Designers get a chance to work on a project separate from the demands of their full time job, and each winning design supports an organization trying to change, even a small part of our world, for the better.