If you think Lego is for kids, then you are wrong!
A new book just came out called "Forbidden LEGO: Build the Models Your Parents Warned You Against!". This full color book contains backroom projects that LEGO's master designers build under the LEGO radar, just to have fun. It teaches you how to build a catapult that shoots M&Ms; a gun that fires LEGO beams; a continuous fire ping-pong ball launcher; and more!
It would be fun to have a lego gun fight at work!! This is good for team building... You can even convert your negative feelings (toward a particular co-worker) into actions.... hahahaha....
Here is an example: