Great idea, but the source image is copyrighted. You can probably find something usable by checking http://www.pxleyes.com/blog/2009/06/how-and-where-to-find-legal-source-images/

CMYK46 is right, the image is copyrighted. You can find similar images on Flickr using the advanced search feature as explained in the blog he suggested.
This link: http://www.flickr.com/search/?q=urinal&l=deriv&ss=2&ct=0&mt=photos&w=all&adv=1#page=0 will take you to the Flickr pages with usable images.
I saw this image which is very similar to the one you used: http://www.flickr.com/photos/stevegarfield/279101205/
You should also check this forum topic: http://www.pxleyes.com/forum/viewtopic.php?f=7&t=3933 here you will find more links to help you learn about Pxleyes.

When I downloaded the source image from Flickr I used the creative commons filter. Is it possible that the owner changed the copyright after?

I reworked the photo with the image Spaceranger recommended. Thanks! Not in violation anymore!

looks a hell of a lot better now anyway.

Ouch... Ouch ouch ouch... ouch ... big freapin OUCH!

hope you have a penny,well done

interesting, good work, bravo

dat's a lots of fun !!! great thinking!!! maybe enlarge the bird just a bit.. just to make it stand out a bit, the puppy is a very powerful visual.. great fun chop

good use of source

Great take on the photo. Nicely done! Very creative.