Yep, it is! Slate.com posted an article about whether it's bettter for the environment to rent locally at a store or rent via Netflix. In a nutshell, Netflix doesn't add the extra fuel burnage sending vidoes to a large warehouse before hitting the store shelves. Plus, having videos delivered with the mail eliminates driving to the store (which burns gas again).
Of course, if you can find options to rent/view on digital cable or online, even better for the environment. Be the solution, while enjoying life!