Robert_Charlton - 7:12 am on Nov 17, 2010 (gmt 0)

I've observed that my tastes match up differently for different things with different friends. I doubt that Google's going to get it right when close friends and I still notice "irreconcilable differences" among us after a great many years.

I should add that collaborative filtering models I've seen almost always get it wrong, as they tend to correlate taste with easily identifiable categories rather than along qualitative lines in apparently dissimilar categories.