I thought I'd share my lighttpd config file. My main application driving http://www.standardbehaviour.com is at ~/web/, which means the dispatch.fcgi file is in ~/web/public/dispatch.fcgi.

# Modules to load {{{1
server.modules              = (
                                "mod_rewrite",
                                "mod_redirect",
                                "mod_access",
                                "mod_fastcgi",
                                "mod_compress",
                                "mod_accesslog" )
# }}}1

# files to check for if .../ is requested

# Mimetype mapping {{{1
mimetype.assign             = (
  ".pdf"          =>      "application/pdf",
  ".sig"          =>      "application/pgp-signature",
  ".spl"          =>      "application/futuresplash",
  ".class"        =>      "application/octet-stream",
  ".ps"           =>      "application/postscript",
  ".torrent"      =>      "application/x-bittorrent",
  ".dvi"          =>      "application/x-dvi",
  ".gz"           =>      "application/x-gzip",
  ".pac"          =>      "application/x-ns-proxy-autoconfig",
  ".swf"          =>      "application/x-shockwave-flash",
  ".tar.gz"       =>      "application/x-tgz",
  ".tgz"          =>      "application/x-tgz",
  ".tar"          =>      "application/x-tar",
  ".zip"          =>      "application/zip",
  ".mp3"          =>      "audio/mpeg",
  ".m3u"          =>      "audio/x-mpegurl",
  ".wma"          =>      "audio/x-ms-wma",
  ".wax"          =>      "audio/x-ms-wax",
  ".ogg"          =>      "audio/x-wav",
  ".wav"          =>      "audio/x-wav",
  ".gif"          =>      "image/gif",
  ".jpg"          =>      "image/jpeg",
  ".jpeg"         =>      "image/jpeg",
  ".png"          =>      "image/png",
  ".xbm"          =>      "image/x-xbitmap",
  ".xpm"          =>      "image/x-xpixmap",
  ".xwd"          =>      "image/x-xwindowdump",
  ".css"          =>      "text/css",
  ".html"         =>      "text/html",
  ".htm"          =>      "text/html",
  ".js"           =>      "text/javascript",
  ".asc"          =>      "text/plain",
  ".c"            =>      "text/plain",
  ".conf"         =>      "text/plain",
  ".text"         =>      "text/plain",
  ".txt"          =>      "text/plain",
  ".dtd"          =>      "text/xml",
  ".xml"          =>      "text/xml",
  ".mpeg"         =>      "video/mpeg",
  ".mpg"          =>      "video/mpeg",
  ".mov"          =>      "video/quicktime",
  ".qt"           =>      "video/quicktime",
  ".avi"          =>      "video/x-msvideo",
  ".asf"          =>      "video/x-ms-asf",
  ".asx"          =>      "video/x-ms-asf",
  ".wmv"          =>      "video/x-ms-wmv",
  ".bz2"          =>      "application/x-bzip",
  ".tbz"          =>      "application/x-bzip-compressed-tar",
  ".tar.bz2"      =>      "application/x-bzip-compressed-tar"
 )
# }}}

server.document-root       = "/home/mveldthuis/web/public/"
server.bind                = "standardbehaviour.com"
server.port                = 8534
server.pid-file            = "/home/mveldthuis/var/run/lighttpd.pid"
server.tag                 = "lighttpd"
server.username            = "mveldthuis"
server.groupname           = "mveldthuis"
accesslog.filename         = "/home/mveldthuis/var/log/lighttpd.access.log"
server.errorlog            = "/home/mveldthuis/var/log/lighttpd.error.log"
server.indexfiles          = ( "index.php", "index.html",
                               "index.htm", "default.htm" )
url.access-deny            = ( "~", ".inc" )

# Main site, I want this on www or no www, and on .com, .net and .org
$HTTP["host"] =~ "(www\.)?standardbehaviour\.(com|net|org)" {
  server.document-root     = "/home/mveldthuis/web/public/"
  server.error-handler-404 = "/dispatch.fcgi"
  fastcgi.server= (".fcgi" =>
    ("StandardBehaviour.com" =>
      (
        "socket" => "/home/mveldthuis/var/lighttpd-fcgi.socket",
        "bin-path" => "/home/mveldthuis/web/public/dispatch.fcgi",
        "bin-environment" => ("RAILS_ENV" => "production" ),
        "max-load-per-proc" => 4,
        "min-procs" => 1,
        "max-procs" => 2,
        "idle-timeout" => 60
      )
    )
  )
}

# This is the images subdomain, serves mainly just the files,
# but I have fileNice there which is PHP.
$HTTP["host"] =~ "images\.standardbehaviour\.(com|net|org)" {
  server.document-root     = "/home/mveldthuis/subdomains/images/"
  server.dir-listing       = "enable"
  server.indexfiles        = ("index.php")
  server.error-handler-404 = "/index.php"
  fastcgi.server = (".php" =>
    ("ImagesStandardBehaviour" =>
      ("socket" => "/home/mveldthuis/var/lighttpd-images-php.socket",
       "bin-path" => "/usr/local/www/cgi-bin/php5-fcgi",
       "bin-environment" =>
         ("PHP_FCGI_CHILDREN" => "1",
          "PHP_FCGI_MAX_REQUESTS" => "2500"
         )
      )
    )
  )
}

# Pretty much the same as images, but then for experiments.
$HTTP["host"] =~ "experiments\.standardbehaviour\.(com|net|org)" {
  server.document-root          = "/home/mveldthuis/subdomains/experiments/"
  server.dir-listing = "enable"
  server.indexfiles  = ("index.php", "index.html")
  fastcgi.server = (".php" =>
    ("ImagesStandardBehaviour" =>
      ("socket" => "/home/mveldthuis/var/lighttpd-images-php.socket",
       "bin-path" => "/usr/local/www/cgi-bin/php5-fcgi",
       "bin-environment" =>
         ("PHP_FCGI_CHILDREN" => "1",
          "PHP_FCGI_MAX_REQUESTS" => "2500"
         )
      )
    )
  )
}

Hope this helps anyone.