Global PDA shipments reached a record high in Q2, market watcher Gartner said today, but is it counting correctly. We don't dispute the company's numbers, but at what point does a smart phone become a PDA and vice versa?

Gartner's numbers - for what they're worth - include some BlackBerry devices, but not others. Shipments of the 71xx series haven't been tallied, for instance. Palm's Treo haven't either, but HP's Treo-like iPaq 60xx series and Nokia's BlackBerry-targeted E61 have been.

The researcher said it defines a PDA as a "data-centric handheld computer weighing less than 1lb [454g] that is primarily designed for use with both hands". Plenty of folk use older BlackBerries one-handed, and we'd argue that the keyboards on the Treo and iPaq work best when used for two-thumb typing.

All these gadgets can do voice telephony and - especially in Nokia's case - will be sold as much as phones as email retrievers. This is a crucial distinction, as Gartner's own numbers show.

Shipments of RIM's PDAs - according to Gartner - fell 1.1 per cent between Q2 2006 and Q2 2005. Palms were down a massive 26.7 per cent, a drop dwarfed only by Nokia's 40.5 per cent quarter-on-quarter shipments slip. HP's PDA sales were down 15.1 per cent.

Of the top five global vendors, only Mio managed to increase its shipments, by 65.4 per cent. It's now the number one PDA supplier in Europe, Gartner said. That's almost entirely due to its focus on GPS-oriented products for car navigation, a trend begun a few years back by Germany's Medion and which the name brands have largely failed to capitalise upon.

In order of volumes, the main PDA suppliers in Q2 were RIM (22.5 per cent of the market), Palm (12.7 per cent), HP (10.4 per cent), Mio (8.2 per cent) and Nokia (4.4 per cent). All the rest together accounted for 41.8 per cent of shipments. Quite a few of the 'others' will be HTC's tablet form-factor connected PDAs offered under a variety of brands. They all do telephony, and are sold as much as phones as data devices, by the way.

What can we conclude from Gartner's numbers? The traditional PDA is a dying breed, though it's demise is perhaps more protracted than some observers might have expected, largely thanks to the low-cost satellite navigation market. Ironically, the GPS arena is increasingly becoming the province of dedicated, navigation-specific devices, cheaper versions of the gadgets PDAs began to displace in the early to mid-2000s. Quite a few are derived from PDA technology and incorporate PDA functionality, but they're not sold as such and, we'd argue, shouldn't therefore count as such.

Devices that do voice and data, no matter how well suited (or not) to either role, should be counted as smart phones, not as PDAs. GPS-oriented PDAs will increasingly be squeezed out by GPS-specific devices. Bye-bye, pure-play PDA. ®