I'm curious, has anyone ever seen a software patent novel enough that it could be considered a "non-obvious" solution to the problem that the inventor is trying to attack?
Various data compression patents seem reasonable to this untrained eye - MP3 & LZW compression come to mind. Of course the duration of software patents is ridiculous, but let's not throw the baby out with the bathwater.
Not true at all. Cryptography Research has patented most of the implementation techniques required to do hardware crypto without being susceptible to differential power analysis (btw: that? My favorite business model ever!). That was almost pure systems research.
Something as arcane as DES is not a "natural law". Crypto algorithms aren't pre-existing (show me a naturally occuring physical process that can be described by a crypto alogrithm), they're not obvious to even experts in the field, and people spend a lot of time trying to get them right. That's the very definition of patentable.
[I know DES isn't patented, and there's plenty of good reasons why you don't want a patented crypto algorithm, but I think they certainly qualify.]