The North American Nature Photography Association (NANPA) is the founder of this day and they take photo submissions to publish in their July/August newsletter issue of Ripples. The only catch is you have to be a member to join and that costs money.
Even if you can't submit a photo to NANPA, I think those of you on Zazzle should still try and go out today and take a nature photo for your store. You can go out in your backyard, to the zoo or on a nature walk in the woods. I don't care where you are, just take the photo today! I'm definitely going to try and do this today, but it might be hard if we get rain over here. If I participate, I will update later and show you all the photo on some products. If you participate, I invite you to leave a comment on this entry to your product(s) so I can check it out. I hope to see you guys get involved! Now here are some products for some inspiration.