Arnold Kling discusses the relative merit of software versus drug patents and brings up everyone's favorite, Amazon's one-click patent. He says that the difference between it and drug patents that makes one-click so objectionable, is that one click is obvious (you could come up with it in an afternoon, and so could anyone else).
I've said before that I think this misses the more fundamental objection: that it seems to patent the end, rather than the means. Buying something using just one click is the thing that is good, rather than the means of a achieving it. So by patenting it, you exclude any possible way of making a website such that one click causes something to be purchased. It is analagous to patenting "quick travel between two destinations" rather than "this specific machine that can get you between two destinations.
Of course, my greatest worry is that such basic interface enhancement is actually non-obvious to the typical software programmer or software interface designer. Heck, if I had a nickel for every time I banged my head on my keyboard due to interface problems, I could buy Amazon out!
I would have posted this comment on the blog I just linked except the they kinda won't let me. But expect to see a lot of ignorant comments about intellectual property there. It's just the nature of the beast.