Hello,
I was thinking of posting today something useful for you guys, and I remembered about something we frequently use for our development, and that is loaders for when you have AJAX or Javascript loading in the background.
I can recommend 2 websites we have used for a very long time: http://www.preloaders.net/ and http://www.ajaxload.info/
You can choose your background and foreground color of the loader, the loader type (preloader.net is richer in examples) and the size of the animation.
Good luck in choosing what you need.
Cosmin | Pixelfind