A while back I started receiving unwanted automated calls on my Motorola Android phone at night. It was an automated service calling my number frequently. It was only a recorded voice on the other side. I didn't want to turn off my ringer incase a call I was expecting came through. It's easy to effectively block a number on your android phone without installing any apps. Just follow these steps: [more]
Add the number as a contact.
Edit the contact.
Tap the menu button and then select "Options".
Select "Send calls directly to voicemail".