Probably should have done that a while ago.

kitt@www$ df -lk . 
Filesystem     1K-blocks     Used Available Use% Mounted on
/dev/root       98502268 92764064   4721636  96% /
kitt@www$ rm -rf apache-logs/
kitt@www$ df -lk .
Filesystem     1K-blocks     Used Available Use% Mounted on
/dev/root       98502268 81767436  15718264  84% /

I also added /books/ and /tags/ to my robots.txt list. The search results for those were only duplicates, and sucked. Will probably reduce my search results by a lot, but seems worth it to remove the duplicate content.