One can only watch so much Blue's Clues and Bob the Builder. (Or as Toddler Girl says, "Bubble Bill!" )
Toddler Girl(3) spotted a wad of bubble wrap in the office one day and asked to play with it. We taped it on the floor in the hallway so she could run up and down to her heart's content.
Toddler Boy(2) is a bit more tentative with bubble wrap so he hung around and watched for a while. He never did want to really run up and down on it but eventually drove the truck on it and seemed to prefer it that way.
To complete the theme, we also watched the Bubble Rap!