Have you heard of or tried out Litespeed? It's a server software that's an alternative to (and completely interchangeable with) Apache. It's not free software like Apache is, unfortunately, but based in their performance reports, it might be worth the dollars. See, Litespeed claims to be much,
much faster that Apache for both static and PHP sites. I've seen some large sites that use Litespeed, so I believe it. Litespeed also handles DDoS attacks better than Apache. Frankly, if I had the cash, I'd definitely use Litespeed instead of Apache.
