The participatory, clubby focus will probably be good for Zeeks. A major theme in the online-kids area is how they love to use the Internet not only to connect with each other, but to share and display their work. Zeeks has thought through the safety issues thoroughly. On top of that, they say, four humans review almost everything the spider turns up as inappropriate, and eight people oversee those four people. Seems a little top heavy, but good intentions, certainly.
Kids just access the child-appropriate stuff on the computer as well as on the Web.
They're simply responsible kids' entertainment providers that keep kids safe within their boundaries. They're designed as clubs so that kids who want to join have to register. Registration spells protection in the sites who do this right. For example, a child has to be a member to chat in or post to discussion boards on these services, and members have gone through that registration screening process. All three are known for their sound kids' safety and privacy policies.