This formal definition points out that there is another category of mobile devices that consumers often confuse with smartphones: the quick messaging devices (QMD) like an LG Xenon that carry a QWERTY keyboard and/or a touchscreen, but run on a proprietary software platform rather than a smartphone OS.

OK, now that we know what we're talking about, here's what our data show:

• Smartphones continued to grow at their 2008 pace. That in itself is pretty impressive, since technologies that are in their initial phase of adoption — which, at 11% of adult US subscribers at the end of 2008, smartphones were — usually exhibit gaudy growth rates that decline precipitously as the base expands. Smartphones reached 17% share of US adult subs, up from 11% at the end of 2008 and 7% a year earlier.  

• QMDs' growth slowed but still eclipsed that of smartphones. QMD penetration nearly doubled in 2008 to reach 9% of adult subs, and had they been able to maintain that pace their would have surpassed that of smartphones, but their growth rate slowed by one-third. Today, 15% of adult subscribers own a QMD. 

• BlackBerry still dominates in smartphones. Yes, despite Apple getting all the attention, even in a market segment that grew by more than half, RIM maintained its two-to-one advantage over the iPhone. Certainly broad availability across all operators and a range of form factors and prices helps, but also some people just want a keyboard, full stop.

What about 2010? This will be the year of the smartphone, now that multiple device OEMs and multiple carriers are offering Android devices, and those ranks will grow (we expect AT&T to join the crowd in the first half of the year) as will the range of Android form factors and prices. That means 2010 is a warning call for Nokia and Microsoft, whose market shares will take a beating if consumers fail to deem their products competitive.Oh yeah, and I think that company in Mountain View may have something in the works…check in tomorrow.