Of late, I have started reading quite a bit on Recommendation Systems and I came accross this interesting paper on the topic. The cool thing is that it talks about virtual co.mmunities based on recommendation systems (I am sure Amazon uses a similar algorithm, since this seems pretty common sense).
On a side note, the paper did lead me to finding out what a Pearson’s Correlation is. Pretty neat. Further links on this entry as I come across ’em