I just downloaded an app on my droid, it's called Spoof. You can put the number you want to show up on someone's caller id when you call them, you can also change your voice and you can record the conversation.
My first call was to one of my best friends. I put in his wife's number when I called. I changed the voice to as deep as it could go. Called and he answered he said hey so I said hey back. He said who is this(thinking it's his wife that's going to be saying hey back). I said "this is the guy fucking your wife in the ass" and then hung up on him. LOLOLOL I didn't tell him for two days. He and his wife argued about it because he called her right back and she had no clue what he was talking about. They just assumed someone in her office was messing with them. I guarantee in the back of his paranoid brain he was wondering if she was cheating on him.
My first call was to one of my best friends. I put in his wife's number when I called. I changed the voice to as deep as it could go. Called and he answered he said hey so I said hey back. He said who is this(thinking it's his wife that's going to be saying hey back). I said "this is the guy fucking your wife in the ass" and then hung up on him. LOLOLOL I didn't tell him for two days. He and his wife argued about it because he called her right back and she had no clue what he was talking about. They just assumed someone in her office was messing with them. I guarantee in the back of his paranoid brain he was wondering if she was cheating on him.