Studying privacy at school has taken me to the wonderful world of online marketing and advertising that is one of the forefronts of the online privacy debate. For example, did you know about Network Advertising Initiative? Neither did I until I heard about it in class. Apparently it's a collection of online marketing companies who try to show that they are doing collective action regarding protecting their consumers. They have guides and all sorts of things there.
One interesting part on their site is that if you click on "Consumer Opt-out", you can actually see which of their members (online advertisers) have placed cookies on your computer. You can then also opt out (which apparently places an "opt-out cookie" on your computer so that they won't track you any more). I haven't heard about most of these companies, yet I seem to have cookies from many. I'm conscious about my privacy in various aspects, but cookies isn't one of those, so I think I won't really bother opting out of these. But it's still refreshing to see to those who don't think about online privacy too deeply and too often. If you surf, you're being tracked by tons of people, and the tools to help you keep tabs on it and control it still have a long way to go.