What are some good phone pranks?

Call a place with a play area like some McDonalds and other local play areas and just after closing hours call up saying you've lost your child there. (put on your best 'black' accent for this!) Get them to search for the child in the play area then if they don't find him/her, say "they call him another name in school that he answers to. what was it again... erm... uhh... NEGRO. yeah negro shout that he answers to that!" and keep asking them to and sound worried

:D

Call a take away place and order a load of expensive stuff and send it to a house across the street and watch them come to thier house with the stuff you ordered and see if they pay for it :)