UPDATED:
The source for the projects as I knew it has been added HERE
What's a forty hour project?
Well, logically, its a project that takes 40 hours to create.
Why would you want to limit the time like that
There are few reasons. Firstly, it means there is a definite end, things actually get finished this way.
So, what else, what good are these projects?
I've started quite alot of projects. I've finished very few. I get side tracked, I find something more interesting to do. 40 Hour projects give me a way of experiementing with another idea without moving completly away from my main project. Hopefully this will give me a way to complete more of the ideas I work on.