A quick list - Wikipedia, Easybib, Blackberrys
I find it incredibly annoying, unrealistic and stubborn when professors refuse to allow students to use Wikipedia. For one, they have now way of preventing me from doing this. I have other issues with citations and the absence of originality, which may be more accurately referred to as authenticity, but that is another discussion entirely. Perhaps not entirely so. Is everything on Wikipedia the distinct property of one person? Is anything? There is a wealth of information and knowledge in the world and Wikpedia has been referred to by Jimmy Wales as the "sum" of it. It seems to me that human knowledge is a continually growing item which will never be counted in its entirety.
In light of Wikipedias ability to highlight and link to other relevant information that can strengthen a paper or an argument, I must say that access to Wikipedia is not only a privilege, but a right of the sensible and modern student. If you want to live in a fantasy world where your pupils make daily trips to the library and read, then do it. I'll be elsewhere.