Its not yet first april, but you can still play this prank on your friends. Ask you friends to call on this number 09371272497 by saying that someone was asking for them. Say it is urgent. When they will call on this number they will be greeted by an unruly female accusing your friend of sending her smses and calling her at odd times... the best part of the call comes when the female hands over the phone to her brother and he starts talking aggressively. Your friend might get scared for a short while.
The sms that I sent everyone read
"Someone was asking about you from this number 09371272497, call asap, seems urgent."