If teaching is to impart (or stuff in) knowledge & educating is to nourish (or pull out), which do we use technology for?
Any technology can be used for either. A wiki can be used to push stuff in such as a chapter summary or it can be used to have students think through the pros and cons of a real life situation. Just because a technology is a Web 2.0 does not make it an educating technology. Videoconferencing can deliver lectures (teaching) or have students share similarities and differences in local folktales (educating). Social bookmarking does not necessarily educate, it can just provide lists of websites (teaching).
How do you use Web 2.0 Tools?