There are plenty of cool spy cameras available on the market today. This Video Camera Pen to iPhone Streamer is another solution that lets you record high-definition 720p video and stream it to your iPhone, iPad, or Android device over a WiFi connection. The camera features a pinhole-sized pen and a microphone.
You will be able to record to a microSD card using this camera. The rechargeable battery inside lasts up to 30 minutes. The video camera pen is compatible with iOS 4.3, Android 2.2, and newer devices. Sets you back under $200.