Windows 7: Themes and Backgrounds

Where I can I get the rest of the Windows themes and backgrounds?
I have Windows 7 Pro 64 bit installed. I love it. I have a great variety of themes and backgrounds installed by default.
However, I've noticed while browsing (and even on the machine I have at work--also Windows 7 Pro 64 bit) that there are different themes and backgrounds for Windows 7.
For example, as I live in Canada, my home version of Windows 7 Pro has a Canadian theme. However, at work an American theme was installed instead. Not a big deal, mind you, but I would like to know where I can get other legitimate Windows themes and backgrounds based on geography, location, etc.

You may find help at Windows 7 Launch - lenovo community. It helped me in several areas.

Check this:
http://windows.microsoft.com/en-us/w...lize?T1=themes

There's a tutorial or two here on unlocking the hidden themes. Take a look at http://www.sevenforums.com/customiza...en-themes.html

The "delivered" hidden themes are for Australia, Canada, United Kingdom, United States & South Africa. In the link, there are instructions on getting Brazil, China, Germany, Spain, France, India, Italy, Japan, Korea, Mexico, Netherlands, Poland, Russia, Turkey, and Taiwan in addition.

Thanks. This is all super information.

Where I can get "full size" wallpaper like on the link below?
http://cache.gizmodo.com/assets/imag...1/500x_04b.jpg