Take the case of Google Latitude for instance. Unless you are like me (a forgetful soul), you might repent sharing your physical location with your near and dear ones. Seriously. And it is even more unfortunate to see official Google Blog saying something like
So now you can do things like see if your spouse is stuck in traffic on the way home from work ...
Pardon my language, but WTF? On a crowded highway, what are you going to achieve by seeing(if you are a strong believer in seeing is believing, that is) that your spouse is caught in a traffic jam? We (still) don't have the technology to muster a Star Trek fame Teleportation. So, what is it that you are going to achieve? That the dear one who has shared her physical location with you is really where she says she is?
I am telling you, you need to be forgetful like I am. If you are not, you need to pretend to forget belongings when desired. Or maybe (hopefully) in a year from now, people will defeat Google Latitude.