The NYT has an interesting story about a Florida trial which was dismissed by the presiding judge when it turned out that eight of the jurors had been doing independent research on the case with the help of their iPhones and Blackberries. The gist of the story is that jurors no longer exist in a controlled environment, subject to just the information that the prosecutor, the defense, and the judge have determined they can consider. They can now look up information on the defendant or on legal precedent all by themselves.
I'm not sure this is as radical a change as the Times describes. I've had access to Lexis-Nexis for more than a decade now, and when I was a juror, I could theoretically look up caselaw at night after the court recessed for the day. Beyond that, except in special cases, the jury is never really sequestered -- the judge just tells jurors not to discuss or research the case until it's been concluded. But how much does this really deter curious jurors? Remember that Henry Fonda's character in "12 Angry Men" did some research on his own, against the judge's orders, procuring evidence that helped acquit the defendant. And that was in 1957, half a century before the invention of the iPhone.
But perhaps such research is now so easy that it's going to require us to rethink how we conduct trials. Maybe we just have to accept that jurors will have more information than we want them to. Or maybe we should go the other direction and wire all juror deliberation rooms with cellular signal jammers, or just build them out of whatever material the Palmer House Hilton lobby is made out of. But it seems like information is only getting easier to come by.