I spoke to Duncan Davidson from the Scottish Drupal Association and they basically grabbed the constituion from the Irish Association and tweaked it slightly from them. They looked into the legal requirements of an association and popped them into the constitution, so it seems like a good starting point.
I've copied their document into a google doc:
Feel free to make comments and suggest alterations here. We'll also need to incorporate changes from the discussion in this forum into that document of course, or use a completely different document. Given people's reaction to suggesting that they would be allowed to edit something via google docs, I'll just sidestep the issue entirely, you can't edit the document. Say in this thread what you think should change, and we'll discuss it. I'm not trying to have crazy influence over the document, suggest something here, and I'll add it. Also, you are also totally free to ignore this document and use something else.
Some interesting points in the documnet though:
This is about these goals: