Why isn't the desk phone dead? I'm talking about the one on the desk of the generic office worker, the cubicle dweller who has a desk with a phone and a PC. I have a mobile phone in my pocket at all times, and spend most of my day in front of a PC that runs Skype (News - Alert). Aren't they a complete substitute?

The phone in my pocket is a consumer-class device, as is the Skype on my PC, so they don't have the features that a business requires in a phone system: corporate phone number, extension dialing, call detail recording, least cost routing, and so on. But all these are easily added to both my phone and my PC using software from the PBX (News - Alert) vendor. Perhaps easily isn't the right word here. There is a vast variety of handsets and to support them all is beyond the capacity of most IT departments.

The classic office desk phone has an incredible user interface. It rings, you pick it up, it connects. In the subtle world of user interfaces, where tiny differences in operation make huge differences in user experience, the cell phone is still far behind this. On most mobile phones you have to find the phone in your pocket or on your desk, and then fumble for the answer button. On the iPhone (News - Alert) you have to swipe a virtual slider – both far clumsier solutions than the simple act of picking up a handset. A computer is even worse than a cell phone in this respect. If it is asleep when the phone rings you have to type in a password, then manipulate a mouse to answer it. And on most PCs the sound quality of the call is atrocious unless you put on a headset, too.

There are times when you need both hands when you are talking on the phone. You can clamp a desk phone handset to your ear with your shoulder. I haven't had much luck using this technique with cell phones. The speaker phone story should be more favorable to the substitutes, because most desk phones have horrible speaker phones. But most PCs and mobile phones are even worse.

The desk phone is superior to the substitutes for the primary function of a phone: answering it when it rings, but the clinching reason that desk phones will be around for a long time to come is simple economics. It's cheaper to stick with them than to pay for something new.