Balloon Tower
For a large number of people:
Equipment: About 20 uninflated balloons per person, Plenty of tape
Optional: Stopwatch or timer, Tape Measure
This is a great game for both team-building and just for fun.
Separate players into, preferably, 3 or more teams of about 3-10 persons each. Each team is given a pile of uninflated balloons and a few rolls of clear tape. Instruct the teams that they are to build the largest free-standing balloon tower possible in a certain amount of time. Give no further restrictions on the game. Start the clock, and everyone begins building the towers. When time is called, look at the towers (measure if necessary) and declare whose tower is tallest. If at a leadership retreat, you can go into detail about what went well and what didn't, and shock (and slightly annoy) the players by suggesting that it would not have been against the rules to combine resources with each other to make a much taller tower. Note on location: Be advised that carpet works quite well, but surfaces like concrete tend to pop the balloons. Experiment ahead of time to make sure the surface is satisfactory.
Blindfolded Mobile/Bag/Shoes & Sandal Shuffle
Required: Blindfolds and Mobiles/Bags
Players: Medium to large groups
Each person puts on a blindfold and will give his Mobile to the instructor. The instructor then keeps the same on the table and then jumbles them all, then shouts GO! The first person to find his Mobile by touch will be announced as the winner.