I've always thought that the best response to "Privacy is less important because I've got nothing to hide" is what I call the "privacy lets you pick your nose" argument. There are plenty of things that we like to do in private, that are not illegal, but which, if revealed publicly, would cause substantial embarrassment. For example, picking your nose, watching porn, lip-syncing to cheesy music in the bathtub.

All of these things create individual pleasure, and thus overall societal utility and value. (That is, they make people happy.) To effectively deny people these individual pleasures by forcing them out into the open would be to reduce overall societal utility. Thus, privacy benefits society by enabling people to engage in legal, but potentially embarrassing, behavior.

(I happen to like Dan Solove's work a lot, and I think he is ultimately coming to the same conclusion as me, but his argument seems to rely on accepting his definition of privacy, while I think that the above argument simply attacks the "I've got nothing to hide" argument head on.)