Orin Kerr over at the Volokh Conspiracy is talking about peremptory challenges in jury selection:

I think Olin is overlooking something important, however. My sense is that peremptory challenges exist in the United States because juries have to be unanimous, at least in most jurisdictions. In a criminal case, every single juror has to agree for the jury to convict or acquit; a single juror can hang a jury and avoid either a conviction or acquittal. When a single juror can control the outcome of a case, it is reasonable to give parties the power to screen out jurors who they see (whether rightly or wrongly) as unrepresentative of the community at large. Peremptories can filter out unrepresentative viewpoints and leave a more accurate picture of core community values and attitudes.

Interestingly enough, today The Truth Laid Bear is complaining about a proposed Ohio Law:

The Amish, who shun judging others under their faith, would be excused from jury service on religious reasons under a bill sent to Governor Bob Taft for a signature...
...
So the idea is to create a legal right to avoid jury duty for a special segment of the population who have a certain set of religious beliefs that the government has decided are deserving of protection not given to any other religious beliefs. (Paging the establishment clause! Establishment clause, please call your office...)

Reading both of these today reminds me of my one jury experience a few years ago. It's a joke in the engineering community that we never ever get picked for a jury. We're too analytical, and lawyers don't like us. So I figured I'd go, maybe get picked for a pool, stand up and say that I was an engineer, and that would be the end of it. Thank you for your time.

As it turns out, the pool I got randomly picked for was for a case involving an assault on a county sheriff. One person in our pool was a lawyer. He and the defense attorney kept trying to figure out if they knew each other, so he was out. The standard question asked of the rest of us was whether we knew any police officers. About half of the candidates answered yes, so they were pretty much out. Then two of the people claimed to be Jehovah's Witnesses, and said that they could not sit in judgment of another person. Actually, I believed the first person who said it. I think the second person just thought it was a good line. After much questioning from the judge, they were out as well.

So by the time all those people were eliminated, I was one of the ones the lawyers were stuck with. Not a typical juror. They even picked a chemistry PhD... probably not too typical either. When it came time to do deliberations, and we voted for a foreman... yours truly was selected. Actually, nobody else wanted to do it, and I volunteered. You should have seen the looks on the lawyer's faces (and also the judges for that matter) when they found out. Priceless.

Next time I have to go to jury duty, I'm wearing my white short sleeved dress shirt with a pocket protector. That will tell them I'm an engineer. You're not supposed to pick me.