One of your classmates questioned the fact that I occasionally use Wikipedia as a source of supplemental information in my slides. I thank him very much for doing so!
This is one of those "do as I say, not as I do" situations.
I know that you've probably been taught (and rightfully so) that Wikipedia isn't a trustworthy or reliable source of information. I agree with this assessment, especially w/r/t written documents such as term papers, marketing research reports, etc.
However, there are times when I'm prepping my lectures and I want to include more information that the book provides, but still want it to be a gloss/overview/snapshot. In these cases, a Wiki entry might be the best way to convey the information in a concise but fairly comprehensive manner. Before I include the page, I make sure that the information contained therein is unbiased and well-sourced.
I know that it might make your other instructors' hair stand on end, and I apologize to you and to them if I've led you astray. I never use Wikipedia as a final source in any other "official" capacity.
Please feel free to discuss this with me further in/out of class, during my office hours, or here on the blog.