well i don't quite understand exactly what bitcoins are (but thanks, max). but i actually think this is the basic approach - if there is any approach - to moving to the post-state phase: you just start coordinating things outside it; you start providing alternatives to it; you start making it possible to ignore it. that was the approach of my man josiah warren, already developing his own currency circa 1830. or lysander spooner, who challenged the government monopoly on postal service and on professional licensing (of lawyers, in particular).
p.s. my book by and about warren, the practical anarchist, originally scheduled to be published feb 2011, has been delayed etc: par for the course. my end is done, and fordham says fall. i'd expect it early 2012.