Real Examples of REST in Action?

Hi all,

Several months ago I read Architectural Styles and the Design of 
Network-based Software Architectures and have since been occasionally 
reading here and other discussions on the web and have come to the 
conclusion that a) most non-HTML web services aren't REST and b) they 
probably should be. I was wondering though, are there any real-world 
(hopefully prominent?) examples of services adhering completely to the 
REST constraints that aren't based around HTML/CSS/JS (minus cookies) or 
Atom? I think it would give me a better sense of what REST looks like in 
practice to see more individual instances.

Thanks,
Shea Levy