My colleague Jim DeLong has an excellent post over at IPCentral.info on the common law's ability to adapt to different social and technological circumstances as it relates to intellectual property laws. I cross-reference it not only as flagrant cross-promotion, but also for the applicability of these principles for the regulatory arena. In particular, I think the contrast between the common law reasoning-style of antitrust with the rigidity of administrative regulation is quite salient. (This contrast is more than a tad ironic since administrative regulation was meant to be adaptable, but maybe it's too adaptable with things like property and contract rights).