Feedback and comments welcome :)
I would suggest you serve those assets via https if at all possible.
Is it possible to preload the image before applying the style? The flashes to what I think is the normal bg image and image loading progress thing makes it harder to compare backgrounds.
Though I'm seeing some requests blocked in Chrome (maybe AdBlock? or something else) when trying to use the bookmarklet on an HTTPS site.
I do have a plea to users of some of these backgrounds. Perhaps I am a tinge obsessive compulsive, but the backgrounds that include uneven specks always make me think I have dust on my monitor that I need to wipe off. So when making a selection, might I ask you to choose a regular pattern rather than ones that are intended to look like spotty paper fiber? That is, of course, unless you are a paper products company. :)
It kills compression too if you use large tiles.
I built this tool to test out Adobe webfonts. I'd like to convert it into a bookmarklet like you did here. Thanks for the inspiration!
http://harrisnovick.com/cygni (move mouse to left browser edge for menu).
If there is a way you can make it keyboard friendly, it would be great.
I'll try to make it more clear you can do this on the landing page.
He deserves 100% of the credit for the patterns, I just created the bookmarklet. And I agree, SubtlePatterns does rock :)