Originally Posted by Gramin

Since nobody is commenting on my thread , I'm going to (partially) hijack this thread. Check out this: https://www.kickstarter.com/projects...ear-headphones.

Granted, not as cheap as $8, but for $200, it detects cadence, heart rate, oxygen, distance, etc. With the right app, this could replace the Garmins. Used in conjunction with a smartphone, the possibilities are awesome.