I wouldn't expect a cellphone in SR (that is, one that isn't specifically an "earpiece" or "wrist" cell) to be as fancy as, say, a Treo 650--or even a Blackberry. Whereas a PocSec would be your run-of-the-mill PDA (even if they based it on the Newton). But it's not something you can rely on them to tell you about. For example, an earpiece cellphone on its face is pretty silly. One without a speaker/mic, but connected to a jawbone earpiece via (encrypted for the shadowy and paranoid, natch) Bluetooth OTOH seems more rational. Especially if it had voice recognition (so to speak) autodialing from one's addressbook.
But then again, this is SR. Reason doesn't usually apply.
Reading SSG, wireless is very popular in SR (although they glossed over the fact that there is no form of wireless transmission of power when mentioning that they did away will all of those nasty cords) and I would have no doubt that were someone so inclined that they could ditch the phone part of said earpiece phone, add a second noise-cancelling Bluetooth earbud and run everything through their PocSec, utilizing it as a calendar, addressbook, hub to connect to their Bluetooth-enabled iPod (which we will see in less than 5 years anyway) and even the laptop in their backpack to read their CrimPro outline which is projected onto their Whitelaw shades (or via their wireless, subdermal datajack to their Image Link if they're from Bellevue.
) while they make notes on the PocSec as they ride the Monorail to U-Dub from their apartment in Renton.