afaik the ps3 uses bluetooth for the connection between machine and controller, same as the wii. The ds uses that other wifi standard (802.11b/g i think).
Then again the wii has a single example (pokemon battle revolution) where the ds can be used as a controller, but i think it 'switches on' input from a wifi source for the wii.
Ideally u'd want an example where the ps3 and the psp interact in some way (like that rear view mirror mode for the psp they promoted with a racing game at e3), to see how that functionality likewise becomes available, if its at all different from the standard data transfer (ie not one way).
It all sounds a bit long winded just for the novelty of using a Nintendo handheld as a controller for a Sony machine. I suppose the irony would be it wouldn't be the first time Nintendo tech has been used for Sony controllers

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