I really like your approach, especially making everyone manager for a week. I think the only problem I see with it is that if people want to find another job, their 37signals title makes it seem that they essentially "went nowhere". So even if you are paying them a lot more then when they started and they are the best customer service person ever, their resume still says: "Jane Doe - Customer Service Rep 2005-2011" which looks unimpressive elsewhere.