A Slashdot-like service should be integrated in the patent review system. It appears to me that, every time there is a new software patent that makes it on Slashdot, in a matter of minutes somebody will find some relevant and non-trivial prior art. Just like the parent poster and others around did. I think that a patent should be pre-issued and be in an informal "challenge" phase. In this phase, the patent could be set up on a moderated website like Slashdot where people can point out the relevant prior art. If the patent remains unchallenged it can be granted, otherwise the patent office can take a couple more days to analyse the top "challengers".
I know that, theoretically, a system like this is already in place, since after the patent is granted it can be challenged in a court of law. However, this system is prone to abuse and too expensive.