Formal or informal?

Learning Technologies 2006 - giving a talk on informal learning but in a quandry. How formal should I be ? Should I use PowerPoint? Dress down? The gist of it all is the idea that informal learning has always been more important then formal learning and that Web 2.0 leads to Learning 2.0, with Google, email, messaging, blogs, wikis, blikis, podcasting, feeds et al pushing formal learning further and further into the background. This is where the real action is on e-learning.

Come along and heckle - that's informal.