Shoe Polish Phone Prank
Coat the reciever of someone's phone with shoe polish and then give them a call. Instant gratification. Make sure you match the colors of the polish and the phone. Small amounts of shaving cream work too.

Three Way Call
Utilizing threeway calling, call two people you don't know and start a confused conversation that goes like, "who is this?", "Who is *this*?", "Why did you call me?", "Call you? You called me!"...

Glue The Reciever Down
Glue the victim's reciever down, and then start making lots of calls to the victim.

Make A Pledge
Call in pledges to your local public TV station in the victim's name. Be generous. Other charities work as well.

Intercom Switch
Switch on the intercom as tell the victim that the "person on the other end wants to talk to you". You'll hear them going "Hello? Hellooo?"...

Multiple Caller Wrong Number Prank
Gather up a group of friends for this one. One after another you and your friends call the victim and ask him if Ronald is there (or some other creative name). Everytime he says, "No you have the wrong number" another friend calls back asking for the same name. After the victim gets really annoyed, you then call him and tell him that you are Ronald and ask him if anyone has been calling for you.

Here Comes The Train!
Call someone on your cell phone next time you are stuck at a rail road crossing and waiting for the train to pass through. As the train gets closer, the person on the other line will be able to hear it. Tell him, "Oh no! Oh no! ...i am stuck on a train track" He will hear the train getting closer and closer then make a loud clapping noise and quickly end the call. Make sure to call him back laughling!! and make sure you tell him the truth.

Congrats! You Won!
Some restaurants have those little prize boxes where you have to fill out the form for a chance to win something. When nobody is paying attention, take a few of them out. Then call those people up and tell them they won the prize! The bigger the prize the more enthusiastic the victim will be. Then tell them they will need to pick up their prize in person. Give them a location far away at an unusual time.

Name Swap
Next time your buddy leaves his phone laying around. Pick it up and change your name in the phonebook with an Ex's name. Then wait a few minutes and give him a call. He will think his Ex is calling him.

Answering Machine Prank
Next time you call your buddy up and he doesn't answer the phone because he is staying home and has a hot date over, try this prank. If he doesn't answer, this means it will go straight to the answering machine. So he and his date will hear the message you leave...this is what you say: "Hey Mr. Smith (or whatever his last name is) this is the video store calling to remind you that you still haven't returned Buff Sexy Gay Men Volume 2...its 3 days late"