I am a wikivangelist. I push wikis wherever I feel they will be the best solution. I even have my CFUW Oakville club using them and believe me they are not the most technological of women :) (sorry ladies, but you really aren't)
I had to push to get wiki software installed at work, but now they are all over the corporation. Our location were early adopters and there was a lot of pushback. Once other departments started seeing what they could do other IT departments installed them and we were off.