Teaching Category Theory on-line resources

At our institute (Informatica-UFRGS, Brazil) there is a group starting to develop a collection of on-line resources to help teaching the Category Theory. Now I am looking for similar work around the world. We are specially interested in exercices and other similar resources available in the net. Could someone give me some links? Thanks in advance, Rodrigo ---- Rodrigo Quites Reis Associate professor at Federal University of Para' (http://www.ufpa.br) D.Sc. C.S. student at UFRGS - Brazil (http://www.inf.ufrgs.br) E-mail: quites@inf.ufrgs.br / quites@ibm.net