Don Demsak is pretty well known in the .NET world, especially by his moniker of DonXML. Don has been an independent consultant for about 12 years. He gets by doing a variety of things (somewhat like what I described in this post?) but was getting frustrated by his work getting in the way of what is fun for him and working with a limited resource - his own time. So he took the plunge and accepted a job that has the potential of enabling him to focus on things that interest him rather than having to find time outside of his workday to work with these things, since most clients don't pay you to sit around and experiment.
There are lot of formulas to be weighed and tested. My formula is that I do my billable work and then I have to find additional time to pursue all of the technologies that fascinate me. But I can occasionally still cut out in the middle of the day and go skiing or take 5 days off to go to a conference and find justification for it. Truly if I want to get my work/life balance back, though, it would be the fun stuff that would have to go - because nobody's paying me to do that. But I'm not ready. Don seems to have found a formula that enables him to pursue his interests as part of his job and at the same time, it sounds like he gets to retain some of his independence too. I can't imagine him any other way!