I have stopped worrying about meta-gaming some time ago. Personally I find randomly rolling perception like checks just to hide the real ones more irritating then players who "might" meta-game the check. In fact, last L5R* session there was a check about knowing whether somebody was not telling the truth. The check failed, which resulted in a longer discussion about metagaming *between* the players (I immediately said I did not care, but the players apparently did) then when I never had asked for the check and let the players decide how their characters would react to the lie 
(The real check was trying to get the NPC reveal the truth through asking the right questions and/or making the right Diplomacy check.)
Yeah, Insight's a real culprit too.
DM: (rolls hidden check) "He says to go left, and you think he's telling the truth."
PC: "Hm. I still don't trust him. I'm going to go the other way."
DM: "No, you can't...."
* No D&D, but when it comes to metagaming and senseless skill checks all games are the same
Not as much anymore. More and more games are coming out in which success on a die roll means that players are actually entitled to create the information they were rolling for. This can be easily incorporated in to D&D, but I doubt it will ever even become an optional suggestion in the rules.
[N]o difference is less easily overcome than the difference of opinion about semi-abstract questions. - L. Tolstoy
