You can now have a conversation with your sneakers in real time, thanks to a new partnership between Apple and Nike. Nike is introducing running shoes with sensors that transmit data – on speed, distance, calories burned, etc. – to a receiver hooked up to your iPod Nano. You can get feedback as you run, and you can upload data to a web site for analysis. You have to admit: It’s pretty ingenious. It also shows why it’s going to be hard to displace the iPod from its dominant market position. Apple is capitalizing on the device’s ubiquity to link it to other products and services. And because it’s a proprietary system, every link-up is another lock-in. As your shoes and your car and your stereo and your clothes become iPod-enabled, it becomes ever more difficult to abandon the little sucker.