In an excellent case study produced by Kineo about the line managers' portal they developed with and for Marks and Spencer. It is available here.
There's lots of gems, including a list of the five key questions you need to ask a subject matter expert if you want to take out the knowledge and build the learning environment. They are excellent and straightforward.
As useful as a wiki can be, soliciting user participation is roughly akin to shepherding a pack of hippos. Users may appear to be indifferent and slow, but, get too close or be too insistent, and watch out. The article gives good ideas on how to use carrots and sticks to drive participation.
Did you know that Nov. 10-14 is National Distance Learning Week? To kick things off, how about a podcast? Here's Conrad Gottfredson speaking about Learning at the Five Moments of Need and the essential role that informal learning plays in performance support.