I've been posting a lot to David Friedman at his blog. David ranges widely on many subjects, and asks questions that are interesting not just because they are topical, but because they are posed from a set of libertarian premises that is unevenly informed by science and reality and also bizarre.
We had a really stimulating discussion at Academic Tabu. David (and others) totally missed the distinction between scientific ideas of race and cline, and thus why human races are a bogus idea. There were side trips on the value of S. J. Gould's "The MIsmeasure Of Man", and the creationist fallacy of whether evidence against a competing hypothesis increases the probability of a remaining hypothesis. A number of others don't get the simple point that genetics could be entirely responsible for all the variation of a character like intelligence within each of two populations, and yet there might be zero variation of intelligence between the two populations. Or that if there is variation between the two populations, it could be entirely due to some environmental influence.
Most recently, "Dishonest Words". There, David plays pot-calling-kettle-black. I also mention a real-life counter-example of the creationist fallacy: the Monte Hall Problem.