There's two things i think would be good.

1. Synchronising the Rio's so that you have two or three playing at a party without echo/delay.

2. Think about interfacing to a standalone VFD device through a serial port. The display on the Rio will never amount to much so getting a display like the one used in the Slimp3 is the way to go. This standalone display could be sent other messages as well, such as send caller id.

bill