I agree that this won't make any difference to people who are totally clueless about browsers and browser compatibility, but extending the idea might make life

I agree that this won't make any difference to people who are totally clueless about browsers and browser compatibility, but extending the idea might make life easier for others; if you could run IE6 in "IE-mode" for a whitelist of sites that you knew required compatibility, "Chrome mode" for all other sites, and toggle between them on demand, wouldn't that be pretty useful? Assuming that you have any need for IE at all, of course. Of course, when you think about that scenario, it starts to seem insidious the other way around. People might be less and less motivated to write cross-compatible websites if it becomes easier and easier to work around incompatibility.