A number of projects from the contributors program and the general project list are models of community-driven development, or of educational tools for children, or of constructionism in practice. Too often we forget in the rush to get everything done how excellent and inspirational are some of the finite projects already underway or in use.
 Brilliant project ideas
 Etoys everywhere
The Etoys Foundation newly set up in Germany has inspired a great many classrooms and teachers. They run their own conferences and organize their own forums and gatherings. They have an entire subset of teachres working on/with Etoys on Sugar.
Over time, this has become one of the more interesting activity development stories. It originally began as a design project within the World Food Program, who wanted to follow up on their successful Food Force game with something designed to run on the XO. A pair of developers in India expanded into 4 and 5 students working on a collaborative version of the originally imagined game, and it is now nearing completion...
Feedbooks.com testing in the field (underway now) has helped focus the network of bokreader projects that existed (from read to read etexts to swordread and browse itself) onto a small set of use cases. In particular, the use cases of making a particular website (with great public domain ebooks) load and render flawlessly. Sending Hadrian (the site owner) an XO for testing helped turn up a number of usability comments that are contributing greatly to current development -- and the idea that he could become an active tester led to prioritizing work on fbreader in the first place.
 Dr. Geo II and classroom testing
Getting children directly engaged in development and improving tools for / surruounding the XO is an essential constructionist act. cf. Pascal's work in Paris.
Sometimes all that is needed to turn a flagging project into a successful one is one great connection. Without widely adopted processes for identifying these needs and facilitating connections, this often means personal intervention from someone who knows a lot of other people and their availability. This is lwonderful when it works, but it doesn't scale ery well, nor is it easy to make transparent the process.
Some examples of projects defined by a great connection:
 Educational blogger platform
Two connections were needed here : Greg and Tony. Greg appointed himself the project manager for the project, and Tony saw to it that any nuts and bolts needed fel into place and had technical (and sometimes shiping!0 support.
Anne Gentle was an essential bridge to making this project idea land on fertile soil within the other organizations she knew. There were some important connections both before and after her, but she was in the thick of it all.