Don't you just hate it when people call and then hang up? That has actually happened to me lots of times already so I believe that Caller Identification is a good idea. It's a site where you can find (or report) any caller that has been "misbehaving". You just write the number down and submit it to the site.
Now, if only our phone's got a caller ID so that I would be able to submit those prank callers that besiege me every now and then, too!