Reviewing the progress of Ta-da List, Jason Fried talks about leaving flexibility for people to make what they will of the tool. I think this is a very important design approach. Too much software in the past has been feature-rich and usefulness-lite, in my opinion. This is why everyone has a favourite tool that they do most things in — the tool that allows them the most flexibility. If you just give your users room to manoeuvre, then they’ll do things you never imagined with the software you give them. And they’ll love you for letting them.