Swimming laps.

It's still funny to me how easy it can be to entertain a child. Take this silly little $25 pool. Bailey gets a kick out of going in it and "swimming". She swims around and around, trying to hold her breath for as many "laps" as she can. I think her record is just shy of five. Of course, she only did that once and really only usually makes it to three. Then, she thought she'd try to "walk" on her hands, dragging her feet behind, but the trick was that she wanted her feet to not touch the bottom. That proved near impossible, but it didn't stop her from trying and cracking herself (and me) up in the process.