Appreciative inquiry has several facets and many applications. It is being used in development work in poor countries (http://appreciativeinquiry.case.edu/practice/organizationDetail.cfm?coid=8734§or=23), education, community development with at-risk youth http://scholar.google.com/url?sa=U&q=http://www.morris.umn.edu/services/cst/symposium/2005/proceed/bliss.citizenleaders.pdf , and with corporations. It is an approach to change that is widely applicable.
Jay talked about it's rejection of problem-solving as an approach to change and it's focus on the positive -- on what is working well in the situation one is interested in seeing change. E.g., In one of David Cooperrider's workshops I attended, f2f, he told the story of helping his son learn to play soccer. Like a good soccer Dad, he videoed his son during games. Then he made a tape of all the things his son had done right and played it back for him. Not one correction!
Another aspect of AI is the focus on collecting data in the form of stories. The inquiry usually begins with people paired asking each other questions that have been prepared. To gain insight into the lifeblood of the group/organization that is changing, questions are asked with stems like "Tell me about a time when . . ." or "What's an example of a time when .. .?"
If we wanted to use AI in this group to explore informal learning and build our sense of being a group, we might use questions. E.g., "Tell me about a time when you got so involved in a situation that it was only afterward that you realized you had been learning a lot." Follow-up: "Is there a time when you realized a week or two later how much you had learned in some (informal) situation?"
The forming of the questions is one of the most important aspects of the process -- I am not suggesting we use appreciative inquiry but I think what question(s) you might ask would help others see where the heart of informal learning is for you/us. I'd be interested in hearing how other people might word a question to elicit a story that would capture the part of informal learning that each of us is most excited about.