[ame=http://www.youtube.com/watch?v=adSZdQTk0nI&feature=player_embedded]YouTube - iLaserPointer.MP4[/ame]
A German company has come up with a collection of add-on gadgets for the iPhone that actually do things in the physical world, not just on the screen. Everything from the simple (a thermometer) to the practical (a flashlight) to the cool but slightly freaky (a stethoscope) to the geektacular (an oscilloscope) are available. You need an app to control some of the accessories (like the laser), but many of them just come on when you plug them in.
HMB-TEC's gadgets (googletrans of German page) are powered by the electrical current from the headphone jack in the iPhone iPod touch and iPad: the devices with the TRRS jack (two rings) that carries current. It's not clear from the website, but the data probe devices like the thermometer and heart monitor presumably use modulated analog to carry info back to the apps.
Sure, there's something goofy about an iPhone fan, but these gizmos show the possibility of a broad range of practical devices powered by the headphone jack and carrying data back to custom apps. The accessories range from the equivalent of about $20 US to around $90, not including shipping costs.
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