Is the stereo in your rehearsal room located too far from your podium? If it is you probably don't use reference recordings and a rehearsal metronome as often as you should. Well if you have an iPod Touch/iPhone and about fifty bucks, you can stream music and metronome from your podium to your stereo. All you need is this device from Sony: The HWS-BTA2W ... catchy name, very easy to remember.
This little device (only about two inches high) is a Bluetooth receiver. Simply plug it in, connect the audio output to your stereo, then "pair" it with your iPod Touch/iPhone. Pairing works just like pairing a Bluetooth ear piece. Just like that, you will be able to stream the audio output of your iPod/iPhone from just about anywhere in the room. No time wasted walking over to the stereo. You can stop/start the metronome instantly (I like "Tempo" or "Dr. Betotte"), or pull up a reference recording on the spot. Pretty cool right?
Another nice feature: You can also transmit audio with these Sony devices, and they will pair with one another. So with two of these (one set to transmit, and one to receive) you can send audio wirelessly from anything that has a headphone jack, so you're not limited to devices with built in Bluetooth like the iPod Touch/iPhone. The only catch is that the Sony device is not battery powered, so you would need AC at your podium if you wanted to use one as a transmitter.
Bluetooth has a range of about 30 feet, so it's not the solution to everything, but for those of us who have multiple rehearsal setups in the same room, this can be a real productivity enhancer, and it sure beats running a long audio cable across the floor.
Update: I forgot to mention that this can also be a nice way to stream from your Mac too, since Macs have Bluetooth audio profiles built in and you can easily pair it with the Sony. Comes in handy when your computer is not near the stereo. The Sony will pair with up to seven devices.