"Wireless sharing is sweet for exchanging music and pictures between Zunes. But wouldn't it be great to be able to actually communicate with another Zuner using your Zune's wireless capability? Well, now you can. Zunerama member Zunadu has created a collection of 1,000 graphics files containing short phrases that can be beamed back and forth between Zunes. The phrases are organized into folders, so you can fairly easily get to the message you're looking for. Zunadu calls his collection "ChikaZune"."
Okay, it's not really the sort of instant messaging we were hoping for, but assuming you have the patience, it's the next best thing. Just try not to hit a hurdle by wanting to say a phrase not contained in the collection of images. Happy squirting. ;-)