Transformer...

Or hide-and-seek grand champion?  You decide!

Hindsight is 20/20.

River just realized that she's made a terrible mistake.

How do I get down from here?

Mine!

River has claimed our stereo for herself.
She just jumped up, turned around and sat there looking at us like this.  Getting her down from something that slippery was fun too. 
After I got her down, she kept looking at the other shelves of the entertainment center as if plotting her next adventure.  They don't make enough baby gates for this.