RPi / Sonos / NextBus
One of my first RPi hacks was to get it to announce via my Sonos every morning when the nearby San Francisco Muni bus was coming. I used a Ruby Gem called muni, the eSpeak TTS engine and the PHPSonos library (the Sonos Ruby gem one I found was quite buggy). The integration works reasonably well and you can find the code at https://github.com/gcapiel/BusAnnouncer. Enjoy and excuse the sloppy code!