Chaordic Puzzle #18

During a school lunch break, ten kids are discussing after school jobs. In particular, they would like to know their average monthly salary (for the ten of them), but no one wants to admit openly exactly what they make. Can you devise a way for them to calculate their average (mean) salary without anyone having to tell anyone else what their individual salaries are?

Solution: School kid #1 enters a "fake salary" into a calculator. He then goes to the back of the ten man line. Number two steps up and enters his real salary, and even if he were to see the original number, he would not see the actual salary for number one...With me? Number three through ten follow suit without being able to know what anyone's salary is. At the end, number one steps back up to the front adds or subtracts the difference from his fake salary that he started off with, and then divides that number by 10.

I received quite some creative alternative solutions. One worth mentioning: all the kids put their salary in a eurocent equivalent in a blinded pot or sack. After number 10, the pot is opened and the total of eurocents is divided by 10.