Work phones are out; personal phones on overtime are in. That’s according to Research in Motion’s director of solutions and alliances (nice title) Rory O’Neill, in any case.

O’Neill made the remarks in an interview in Mobile Today plugging Blackberry software which can effectively build a Chinese wall separating work from personal phone use.

The move makes sense for RIM, long a tech provider with more than a passing interest in the business user and a burgeoning personal use customer base.

According to Ofcom’s last report into the communications market, the ever-increasing popularity of BBM means that 37% of those aged 12-24 now have a Blackberry handset.

But does it make sense for businesses? I’m not so sure.

Really Rory?

“People want their music, data, games, photos, contents and contacts on their phones. But if the phone is supplied by work it is going to have a very individual persona on it, but also some very specific content from the enterprise on it too – and that can be a problem.” O’Neill says in the interview.

No kidding.

There’s no arguing with the fact that many businesses could improve efficiency by allowing their employees to work outside of the office but allowing them to do that on their personal devices is fraught with difficulties, particularly for IT managers attempting to keep everyone on the same page.

In reality, only businesses that exclusively employ frantically BBMing teens will be able to make use of RIM’s solution.

In the actual office, even a small one, different devices, networks and operating systems create a headache for anyone hoping to, say, share a particular app to allow everyone to record their expenses in one place.

And even with that in place, privacy and security issues proliferate.

The more places documents are shared the more likely they are to fall out of employee hands, no matter how many times you write ‘Confidential’ in the filename.