Matt describes how he turns off an annoying feature of IE. I certainly understand where he’s coming from (I hate the image toolbar and turn it off in IE’s options on every PC I use), but breaking standard browser behavior is a mistake.
When people come to your site, they are still using their browser and are comfortable with their browsing environment. Power users know that they can usually accomplish the same thing 3 or 4 different ways in their browser; casual users do not. Casual users know one way to do something and rely on that one way working for them.
Casual users react to broken or missing expected functionality with concern and trepidation. If users aren’t comfortable being at your site, they aren’t going to stay for long. Whether you’re building a web site or a web application, it is very important to make sure common functionality still works.
One of the things I like doing in my web software is using a lot of DHTML to create a rich user experience. Often when this is done, common functionality gets broken because things are not done in common ways. If you are a developer and you find yourself saying ‘they can just do it this way instead’, you’re in trouble. I don’t have a perfect track record, but I try very hard not to break things if I can avoid it.