This script solves the excessive re-spawning problem that surfaces with Tiger-era launchd scripts. Tested using Lighttpd 1.4.18 and OS X 10.5.1.

Obviously, you may need to point to /usr/local/bin/lighttpd-start if you installed with --prefix=/usr/local

Put this at: /Library/LaunchDaemons/net.lighttpd.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
        <key>Label</key>
        <string>net.lighttpd</string>
        <key>ProgramArguments</key>
        <array>
            <string>/usr/bin/lighttpd-start</string>
        </array>
    <key>RunAtLoad</key>
    <true/>
</dict>
</plist>