I'm working on a school project where I was hoping to use a board about the size of the nano that had wireless comm. capabilities. I've been reading up on Xbee, seems like shield would take away any size advantage the nano provides (if they are even compatible at all).
The xbee shield is designed to mate directly with an Arduino Duemilanive, or other boards with the same form factor. The nano does not have the same layout or attached headers for the xbee shields to attach to.
In my opinion, the xbee shield is one of the stupidest shields on the market. I does not expose all the pins below it, like a good shield should. It's incompatible with most other shields, requiring it to be on top. While it's antenna requirements make that almost a necessity, the shield design shouldn't mandate it.
Of course there is. It just won't be by adding a xbee shield, like you would on a Duemilanove. Sparkfun make a xbee breakout board that you can add whatever style headers to that you want: