Front Camera
Click the button and the phone will take a picture with the front camera and send it to your mail. Requires android 2.3. If you have an older version of android it will default to the rear camera. And yes, I know that it is not yet perfect and there is a quick popup.
Rear Camera
Click the button and the phone will take a picture with the rear camera and send it to your mail. The phone will take the picture in the lowest possible quality which is 640x480 and around 100k on my phone.