I know extremely few people who carry around more than one mobile phone with them. Those few that do, however, often carry a smartphone alongside a decidedly less "smart" phone (like that free Nokia that you get when you sign up for new cell service—it works and looks like a brick house).

iPhone users never seem to fall into this group though—despite some gripes about AT&T's (anecdotally horrible) service, they tend to be pretty happy with one device. Or so I thought. According to new report by Rubicon Consulting, more than a third of iPhone users carry around other, second phones with them. Not only that, but a decent chunk of those second phones are other smartphones.

Rubicon conducted a "detailed survey" on 460 randomly chosen iPhone users (a number that our staff PhDs tell me is enough to be considered "not crap") and found that 36.4 percent carry a second device. Surprisingly, the largest chunk of that 36.4 percent belongs to BlackBerry at 9.8 percent—the only explanation we can think of for this is that people are issued BlackBerrys for work and keep iPhones for personal use. However, another 6.1 percent reported using a Windows Mobile device (now that's just crazy). 6.6 percent carry a Motorola RAZR, and the rest were split among Palm, Symbian, Sidekicks, and "other" devices.

Rubicon notes that this is just a snapshot, and the company isn't sure what will happen with the trends over time. "As Apple adds Microsoft Exchange compatibility to the iPhone, it's possible that some of the dual users will discard their Blackberries," wrote the company. "On the other hand, the people carrying both may be doing so because they want to use the Blackberry's built-in keyboard to type messages, and Apple has announced no plans for an iPhone with a keyboard."

Now, I might just be a purist when it comes to minimizing the crap I carry around with me, but statistically, some of you have to be carrying around more than one phone. Fess up: Who are you, and why do you torture yourselves like that?