This simple idea has been a great hit with Baby Bean. We filled a plastic bottle with water, washing up liquid and some food colouring and secured the lid tightly. I think I will do another one and add some glitter and maybe a couple of small objects for interest. My little one loved rolling it and watching the bubbles appear and listening to the water sloshing. We also used it on the floor where he rolled it and made efforts to get to it- ensure the lid is on tightly though!