(Jimmy Wales jwales@bomis.com): On the "every little bit helps" theory, I've offloaded wiki.png to a different machine for now. At least that's going to free up some httpd's to do something else.
You might move the stylesheets over there as well. The software is also quite happy to serve all images from a different site, but that's more work because you have to set up an NFS share for uploads.