You have a sickness. You know it, I know it, and your significant others know it.You suffer from "Continuous Partial Attention."
It means exactly what you suspect it means. It means that while you're strolling down the avenue with your spouse, you're surreptitiously checking your Treo for new messages. You check voicemail while she's in the ladies' room. Admit it: you even do a li'l SMS while in traffic. (And sometimes, when you're crusing down the highway. You may as well be driving drunk, you know.)
Linda Stone, a former Microsoft & Apple exec, coined the term at a tradeshow attended by Newsweek's Steven Levy, who subsequently wrote this article (which I found via Brendan Hodgson at H&K). In Levy's article, Ms. Stone described Continuous Partial Attention as "stemming from our desire...to be a live node on the network."
Who knew? The Borg 'R' Us.