I need a good prank to scare my friends outta their minds!!!! Please help!!!!!!?

Ok so me and my brother were home alone and two of my friends came and ran around our house banging on all of the windows and stuff. Me and my brother freaked out cuz we didnt know it was them. Now i need a really good prank along the same lines. I cant go into their house, but i was thinking of something kinda like what they did to me but i would hide in a trash can and put it in front of there door and jump out and yell when they came out and saw it. If any one has better suggestions please share!!!!!!!!!!!!!!