For something to do indoors that burns energy but doesn't require a ton of space. This is great for a wide age range.
* Rinse out 7- 2 liter bottles
* Optional: Remove the labels
* Fill them up with about 3 inches of water (just enough so they won't just fall over if you brush againest them)
* Optional : Add a few drops of food coloring for fun
Set them up in a triangle and give your kiddo a semi hard ball and teach him/her how to knock the pins down.
My little one rolled into them, literally for an hour, giggling away.