Go outside in the sun and play this game 
http://www.youtube.com/watch?v=Ied34cPqB5M
This is a great game but I had to modify it to deal with the fact that I have limited space in my classroom.
Instead of running away when the magic word is said the students race to sit down. The last one to sit down replaces the person who is 'it' (and responding to who is she/he). Before the class we cleared the desks so we had plenty of space for the students.
I demonstrated the game with the Co-teacher and then got some students to join us.
We had two phases one with who is he?, and the second with who is she?
The students enjoyed the game (and it is nice joining in with the students as you monitor the game). My co-teacher said she would be trying this game with her third grade class.
I advise placing the key words such mother, father, brother etc. on the board so students can use this to help them play the game as I noted some students looking towards the TV where I had the key phrases displayed.
It is an excellent game to practice speaking and listening to the key phrases of the lesson.