Jon,
Venture capitalists sponsor public events just like any other
organizations which want to set themselves apart from their
competition. E.g.,
http://etl.stanford.edu/about/
Absolutely. In particular, they like to get their name in front of
promising entrepreneurs, as finding interesting companies is essential for
their business. So if you pitch them, I'd try to find some reason they can
see it as a useful marketing expense.
Alternatively, rather than pitching venture capital funds, it might be
worth talking to individual venture capitalists, who are just the sort of
person to be fascinated by Wikis. For example, Mitch Kapor and Vinod
Khosla are both tech investors and major Wikipedia donors.
William