Mobile Stethoscope allows you to see your heart beat on the iPhone. Record heart sounds. Send by email. Does not require any special hardware.
Simple instructions: Launch app and hold microphone on base of device on chest area directly on skin. This should be done in a quiet area.
Depending on where the device is held, different heart sounds are emphasized. More information on auscultation can be found at the mobilestethoscope.com site.