I came across Tikatok today via GeekDad, and it's a cool idea that I hope to try with my own children. As Ken points out, there's nothing really new here, except that this is targeted at a different audience:
Obviously this is not unlike other print-on-demand services around the internet, but I like the kid- and family-focus, and the enrichment it could offer to a child to have something they create assembled into something they can hold in their hands, or bring to preschool and share with their friends.
The feel of the site puts me in mind of Flickr or other sites that have gotten the experience of making or doing something right. It's not that your uncle couldn't upload his photos and share them with you before Flickr; it's just way, way easier now, and the tool is meant for him (I know, your uncle has always used ftp/ssh, and good for him).
It also reminded me of of something my wife asked last week. She has an old laptop with a small screen that she loves, and Gmail doesn't use her screen very efficiently. "Can you make Gmail look like this?" she asked, showing me what she wanted. Fifteen minutes of playing with Stylish, Firebug, and Gmail and it's done (well, almost--she has other ideas now that she sees how easy it was).
So what if there was a site where people could say, "Hey, I want the web to work like this..." and then people in the community could see what's wanted and do it as the spirit moved them? Don't tell me that it already exists. Sure, but that's not meant for the people I'm thinking of now. Much as Tikatok does print-on-demand for kids, I'm thinking of a way to let Firefox end-users become involved in the process of creating Mozilla and the open web. Things mean more to you when you've had a hand in creating them.
Let me start the process: "We need a site that lets end-users become part of the creation of the open web."