Over the last week, the VPS serving my sites started getting out-of-memory errors. Instead of debugging while processes fail to start (never fun), I got out my chainsaw and cut down the biggest memory hog, apache2.

Everything is now running on lighttpd as CGI or fast-cgi. I've tested the heavily used sites and they're working fine. The infrequently used stuff may not be as I've not tested it yet. For now, though, I have some breathing room in which to find and profile the memory spiker.

Have you tried out nginx? Most people I know who have used both really seem to like it. Of course experimentation comes in a distant third to making sure everything is working and debugging mis-behaving processes. --Theo
Yup, we run nginx at work; wanted to try lighttpd. So far, so good. ;)