Actually, lots of people, or at least lots of businesses don't.

• Anybody in defense or homeland security. At most of these companies, having a camera or recording device of any kind on your person is a "walk you to the door right now with no advance warning and no appeal" kind of event. If you're in a particularly sensitive area, there could be criminal charges as well. You don't see this much in New York, but having been through a couple of interviews with some of these guys, I can tell you it's reality for many of these folks. By and large this is a DOD/Homeland Security requirement, not a company-specific policy.
• Lots of companies developing sensitive tech. Intel has banned camera phones from their facilities, just as they had always banned cameras in the past.
• Anybody in the legal profession. Federal and many state courthouses don't permit them.
• Lots of other "sensitive" facilities which these days covers everything from sewers to powerplants to water purification facilities.
• I've heard, but can't confirm, that at least one of the major production studios will not permit cameraphones onto the sets of at least some films. (Though knowing the Hollywood hierarchy, I suspect this kind of rule applies to some people more than others.)
• Financial institutions are increasingly sensitive to having employees who handle customer personal information have any technology with them at all. There's some variability, but cameras are almost always a no. Since text messaging has come along, many have found the need to ban all mobile phones.
• Anybody who caters to any of the above on a regular basis may have to comply with the rules of whoever they're working for. This covers everybody from consultants to i-Bankers to janitorial services companies.

I hear more and more clamor for "good" phones that don't have the cameras in them. Lawyer friends are particularly vocal, but I know a bunch of consultants who took on a gig at NOC, only to find that they had to either trade in their Treos for something cameraless or leave them in the car... Some would argue that this is a bit silly. Anybody who is serious about espionage could easily hide a small camera in a shirt button or similar for not much money. My own perspective is that it's not that simple. If by blocking access to "casual" camera users I can avoid unintended breaches of security (for example, a person who takes a picture of a work buddy in the plant at Boeing, and then posts it on myspace for all to see what's in the background), I can then spend a lot more of my resources to deal with the people who are intending to do damage. I don't expect these rules to change anytime soon, and those who really want to serve the corporate market will have to provide phones to match. Can't tell you how many trial lawyers I know who are running around with the $29.95 model because those who don't want or need the Blackberry have very little choice.

-btc