awesome scavenger hunts -- fun reading practice and great independent activity for kids! Many are designed for kids at home, but the idea could be adapted for the ESL classroom - vocabulary development, etc.
HUNGRY HUMAN HIPPOS Get some carpet dollies or champion scooter boards with handles and make this happen. You can use bungies or ropes to pull them back after they have collected as many balloons as possible.
DIY: Bubble recipe and refill station. Love the idea of reusing plastic cups from restaurants as the containers. Keep the bubble solution confined to one big refill container, and no worries about leaky, yucky containers hiding all over the house!