I stumbled across a wiki called FieldFindr. The wiki is a mock-up of a website that would help match a class or class project with a real world expert in the related field.
The wiki was created by blogger David Truss after he posted on his blog about the idea.

“Fieldfindr: A space where teachers can meet global citizens who have skills that they are willing to contribute to a class.”

Some of the comments on his post were concerns about how to validate the person’s credentials and how to protect the students. I hope someone can address those issues and run with this. The blog article was posted back in February so no one has jumped in but I can see a lot of value in this. We already do some of this within our community and maybe this is a project that would be best tied to a community portal. It would be easier to monitor and because of geographical proximity allow for the person to actually visit the class.