As I've commented before, I use wikidot as my commonplace book for hosting online notes.
I used to use wetpaint, but moved to wikidot because of its less intrusive advertising. One nice feature they have is 'other interesting sites', which they add as banner below (can banners be below) to the bottom of pages displayed from free accounts.
And one thing that strikes me is just how many academic wikis there are - be they an applied mathematics page from a university in Portugal, a Brazilian project to collect material on south American languages or a project to document Tibetan monasteries.
So my question is, to what extent are we seeing research projects being hosted on wikidot rather than having projects install and run their own wiki server, and as a supplemental, given the increasing need to capture the scholarly outputs of institutions for reporting purposes, does this represent material that has sneaked under the wire?
(And the unspoken implication, what should institutions be doing about providing wiki hosting services ....?)