Case Studies of Informal or Social Learning

I'm looking to find lots of examples of where informal or social learning has been used successfully in the workplace and where it was led by the L&D organization. This can either be already written up, or it can be the name of a person and organization where it was done.

Can you provide me pointers?

If you would be more comfortable, feel free to send me information via an email: akarrer@techempower.com.