Designer Steve Hunt's gorgeous Halo bicycle lock has already sold us on its looks, but it's got a neat claim to fame to boot: wireless security. If anyone tampers with the Halo and/or makes off with your bike, you'll know about it right when it happens.
The Halo utilizes a Wi-Fi enabled SD card called an Eye-Fi that you'll find in digital cameras and the like. When it detects something's up, it shoots a notification to whatever handheld you've told it to. Of course, that means you need to park your bike somewhere in a Wi-Fi hotspot so the Eye-Fi can do its business, which is the Halo's biggest drawback.
The Halo is just a concept at this time, and will probably stay that way until a more practical alert system than one dependent on Wi-Fi can be sorted out. A bike lock that alerts you, though, is a great idea.