How do I turn off reverse lookups? It's enabled and I think it's slowing my box down.

This is usually a good idea as it is a performance drain and there are tools to convert your logs after the fact. Just look for this line in your httpd.conf:

HostnameLookups on

and change "on" to off.

There after if you need to resolve hostnames for your log analysis tools you can use logresolve which comes with Apache and SWS.