Seeing that we can use equirectangular environment textures in cycles, I decided to check and see what I could find on flickr that had a creative commons license for equirectangular images. Well I was happy to find a ton of great images! So I thought I would share here.
While most of these may not be perfect, for quick and dirty lighting and background I think this might come in very handy! Especially with the variety of images that are available.