Okay, this is a really geeky one to start the week with.. but I love it (you know me). Imagine using your Sony Ericssoncell phone to drive a Keynote presentation, remote control iTunes, DVD Player or any scriptable application on your Mac via Bluetooth..
Maybe the coolest touch is the ability to setup the proximity sensor: choose an action to execute when you leave or reenter the Bluetooth radius. iTunes or DVD Player pauses, your Mac welcomes you back, locks your screen, etc. Beta version functional until March 1st. Available through VersionTracker (it wasn't available from the developer's website as yet). 2003-02-25 update: here's the Slashdot thread and a soon to come AppleScript section on the product's website.