What I find irritating about all the software patent discussion is that patents are intended to benefit society - that is their purpose, "To promote the Progress of Science and useful Arts". But no one seems to want to reason about whether that is actually happening - that would mean doing things like thinking about how likely the invention was to be independely discovered soon anyway, estimating the multiplier of having the invention be in the public domain, etc. Instead we get regurgitation of this meme about making sure the little guy working in his basement gets compensated for his invention.
It's a good reminder. The point of patents is to make society better off.
The standard argument for patents requires, among other assumptions, that the patented inventions require a significant level of investment that would not otherwise occur. As Paul points out, that is not the case for software:
Software patents rarely make sense because software development requires almost no capital investment, and as a result, it is almost impossible for an individual to develop some software invention that would not be discovered by multiple other people soon in the future. Do you know of any individual or organization that is even capable of creating some software "invention" that would not be rediscovered independently anyway in the next five or ten years? I don't. No one is that far ahead of everyone else in software, precisely because there is no capital investment required and no real barriers to entry.
I have read many posts where people try to fine tune software patents to make them less awful. I wish we could instead start by considering the more fundamental issue. Do we want software patents at all?