Wikis

I am not sure about Wikis. They may be 'quick' but how accurate are they if anybody can add or delete information. How helpful would it be in a library to information that is not entirely reliable.
However in saying all that I don't really know enough about wikis to be confident in using them. I have not had any occasion as yet to use them but I know my children use wikipedia a lot and I have looked at that site now and then to gain general information.
So much to learn, so little time!! Poor teddy bear.