I got one of these exercise pens for when we go camping:
http://www.petco.com/product_info.as...Pet+Yards&ct3=
It folds up to where it is only 24 x 24 and maybe 3 inches deep...
It makes it pretty easy to store. When it is set up it is a pretty nice area to play in. I also like that it doesn't obstruct their view- they can see everything going on around them so they don't feel like they are being confined. (even though they are...
)
I didn't get mine from Petco, I found mine at Tractor Supply- it was a little cheaper than Petco's version...