Last night (2006-08-08), I gave a talk on LifeHacking at CPLUG [PDF ODP PPT], which summarized Danny O'Brien's 2004 Emerging Technologies conference talk and put it in context of basic Information Processing theory.
O'Brien emailed several "alpha-geeks" and asked them about their daily interactions with computers and how they did things. The problem with this is that O'Brien's report is biased towards tools. While proper tools are important, they aren't the only differentiating factor in productivity from person to person.
If anyone qualifies for over-prolific alpha-geek status, it's probably Dennis Ritchie and Ken Thompson, but look at what they had to work with (paper displays?). Ignoring the tools, we can see that they're having fun working on something they are really interested in, and there's probably not much in terms of interruptions.
So how do you get from where your life is now to that kind of life? That's lifehacking.