I think I came up with a solution that will fix MacMegasite’s heavy resource usage. A lot of my hits – maybe 60% – are coming from RSS readers. I’m already using FeedBurner to process my feeds. Until now I was using a hack to cause /node/feed to redirect to the FeedBurner URL and Drupal’s URL alias features to map other common feed URLs such as backend.php & index.rss to /node/feed. Instead of letting Drupal do the work, I’m now using Redirect permanent in my .htaccess to redirect /node/feed and the other URLs to FeedBurner.