Here're some iPod Nano watches you would surely love. They are plastic-silicon and you just pop your Nano in and out for charging and what not.
Features include: Custom premium silicone strap, Pop-in pop-out design, Integrated control buttons, Audio port cover with inline orientation, Improves protection.
The $24.95 Hex band has a pop-in design which incorporates the Nano into the watch (as opposed to just sticking it on a band, like the first one did). It has integrated control buttons and comes in 9 colors.