well, you have all of your hits, even things like terms and conditions, privacy policy, etc, going through "do.pl". it's no wonder there's so much load.
probably doesn't help that your "random image of the day" comes from a site without password protection/referrer protection/cross-server authentication:
http://digibucks.com/drive2/members/
i'm guessing do.pl is some template parser, but it must have a lot of code to handle all that stuff. sometimes monolithic programs are nice, but often they are the cause of major performance problems.
but go ahead, don't let me stop you from spending probably at least $10K-20K (you need at least two load balancer servers on the front end, so if one goes down you're still up, plus the handful of backend servers) ;)