Hide and show fields based on the logged in user

There have been a lot of requests on how to hide and show fields since my earlier postings regarding hiding and showing fields and rows. John Straumann has written an article about this before. A working solution, but not too nice though.Here's another solution which is unsupported (ofcourse ;) ), but it gives you a lot more freedom.So how to tackle this problem. We already know how to hide and