As our smart phones get smarter, they become more and more like computers, and less and less like phones. One piece of equipment that we’ve had on computers for decades is now making its way onto our phones. That piece of equipment is the keyboard. The problem is, each handset’s keyboard is different from every other handset.

To me, the keyboard on the device should be one of the biggest deciding factors when selecting a new phone. Some devices have only on-screen keyboards, some have physical keyboards, and some have both.

My personal device, a Samsung Moment, has both an on-screen keyboard and a physical slide out keyboard. I find that if I’m simply entering a word or two, the on-screen keyboard will do. On the other hand, if I’m sending an text message, typing a quick email, updating twitter, entering a URL into the browser, or any other activity that requires more than a few keystrokes, I find the physical keyboard to be much more usable.

If you’re in the market for a smart phone, be sure to take time to try out the different keyboard options on different handsets. There will be differences between the onscreen keyboards and the physical keyboards from phone to phone, and there is no doubt, if you buy a smart phone, you will ultimately be using the keyboard on a regular basis to input data.

The folks over at PC PRO have an article comparing the usability of keyboards across a handful of devices. Check it out, and see their results. You’ll notice that the error rates for on screen keyboards are much higher than for physical keyboards. In addition to the higher error rates, the time required was also much longer.