Look at the PDF from my eye view you could fit two side to side and it would be the same size as the rio. Oh and the rio is twice as thick so make that the iPod is 4x smaller (This is aprox from eye viewing of the pdf above)
Might as well buy an archos duke box....
This is no iPod killer... Small and easy to use it ain't the ONLY anvantage is it's size.....
Remember the iPod has th advantage on macs of connecting to iTunes very well.
Cheers Edd
p.s. Arrived back home today from uni and my iPod was there waiting to be picked up...