Q: Can I use the iPhone stereo headset to control (play pause) my iPod touch or iPod nano?
A: Unfortunately, no. The iPhone stereo headset has additional connectors for a microphone and iPhone control channel that are not present on the other iPod models. There are basically no inputs in the headphone jack to provide any kind of remote control capability.
To provide remote control of an iPod device, you will need an accessory that uses the Dock Connector such as the Apple FM Radio Remote (iLounge rating: A-).