Here's a cool new gadget Engadget found this week. The NetStream DoorLinx, a new high-tech doorbell that features support for MP3 files:
It features an amplified 4-W speaker and embedded microphone integrated into the wall unit (pictured above) and a door latch activation relay to automatically open the door or gate from any NetStream TouchLinX interface.
The magic though, comes when deployed along side NetStream's DigiLinX audio-distribution system so that you (the dealer anyway) can map any MP3 audio file (up to 500KB) to the door chime. When someone hits the button, the MP3 plays in any assigned speaker, anywhere in the house.