Stackable iPod Dock Features As Many Air Filters as You Want

This iPod dock concept seems pretty feasible, if not incredibly practical in its current form: You can stack as many of the pods as you want underneath the dock itself, allowing for multiple speakers, lights, or (oddly) air purifiers.

We like the idea of being able to add attachments to an iPod dock, since they're usually incredibly boring, but this concept could be so much cooler and/or wackier. Air purifiers are pretty gimmicky, but not too interesting—how about adding a photo printer? Or a Blu-Ray deck? Or an aquarium? The list goes on and on. What would you guys like to see as an add-on to a dock? [Yanko Design]