Well, could manage to solve this problem in the picaxe forums.

This may not look very interesting to you, but if I told you that it communicates with the computer the say way that nspires can communicate?
We could maybe do virtually anything the immagination lets us to: ndless can use RS232 (I think) so it my communicate with the PICAXE microcontroler.

In a very simple example: it could be possible to turn on/off your room's light with the press of the enter key by simply using a relay, the PICAXE, a nspire and a lua program to send signals through the print() function.

I didn't tryed anything, but it communicates with the computer through serial port, there could be a feasible chance of making them exchange data.

To make a simpler thing like turning a light on/off I could use an interrupt on an input connected to the nspire just like jimbauwens connected the speaker.
Then any interrupt signal could be used to turn on/off anything...

Simple!