/ol recently brought up an ancient argument regarding time metrics and the net which might be a successful compromise for the ugly warts that software patents are.

Postulating the idea of Internet Time, we could look at a term for Internet-relevant patents of about 3 realtime-years. 3 years seem to be suitable: not exactly nothing and thus likely good enough to give the inventor time to exploit his leadership, but not enough to block a competitor forever. Given such a proposal, you wouldn't have to argue that software is a different field of technology where patents do not make sense. The only line of argument to cover is that the rate of development for software and the like is so much faster that a patent term of 20 realtime-years corresponds to over 100 years in other areas. A real-world analogy: should a car maker really need a license to build a diesel engine today?"

(argument translated and paraphrased by me.)

This very idea can also be found here.