Snowball Fight...kids write 3 things about themselves on a sheet of white paper. They do not write their names on the paper. Wad it up and on your command, have a "snowball" (or baseball) fight. At the end of 1 minute, each student grabs the nearest snowball and tries to guess who wrote it. Would be great at the beginning of the year!
Who Makes the Rules in a Classroom? Seven Ideas About Rule-making
"I did this last year and the kids loved it!! Countdown to last day of school. Pop one balloon each day. Inside is a special surprise for the day. Ex. No homework, read outside, work with no shoes on, chew gum in the morning, etc."