Just a quick hack to listen to xPL notifications and display them on screen. If you activate the xPL plugin on your squeezebox then you can get "now playing" popups. You can always replace pynotify with growl or whatever you use.

now playing for squeezeboxes

#!/usr/bin/env python

import select
import socket
import sys
import re
import pynotify


MAX_MESSAGE_SIZE = 1500
XPL_PORT = 3865

UDPSock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

try:
    UDPSock.bind(("0.0.0.0", XPL_PORT))
except:
    print "Couldn't bind to xPL port"
    sys.exit(1)

pynotify.init("Now Playing")

while True:
    readable, writeable, exceptional = select.select([UDPSock], [], [])
    last_message = ""

    if len(readable) == 1:
        data, addr = UDPSock.recvfrom(MAX_MESSAGE_SIZE)
        artist = re.search("^ARTIST=(.+)$", data, re.MULTILINE)
        album = re.search("^ALBUM=(.+)$", data, re.MULTILINE)
        track = re.search("^TRACK=(.+)$", data, re.MULTILINE)
        message = artist.group(1) if artist is not None else ""
        if album is not None:
            message += "\n" + album.group(1)
        if track is not None:
            message += "\n" + track.group(1)

        if len(message) > 0 and message != last_message:
            notice = pynotify.Notification('Now Playing', message)
            notice.show()
            last_message = message