Clojurians Log v2

Seems pretty idiomatic to me. One thing I noticed is you could probably use (reduce +) in place of (reduce #(map + %1 %2))

...and I have a hunch that you could find something a little simpler than (filter #(apply = %)), though I can't think of it offhand. (Using apply like this is a faint code smell to me personally, though it certainly has its place)