I can see the logic in the model release. But surely if you wave an official looking document under someones nose and you ask for a signature you're going to get a flat refusal, especially if you're not paying them?
Thanks for the legal perspective, I'm always pleased to be made aware of the level headed and commercially minded aspects to this. Not being so business savvy myself.
Although, I'm more concerned with the clash of private, personal and professional interests, when taking and displaying images that will be in the public domain without approval from the person who it most affects.