Ok, but if you can start engine, open windows, etc with the car alarm remote control, if i not wrong use a infrared signal, just need to put the infrared, conected to the car system and then the app of the N900.

That's teorically speaking.

Someone should do an app to put on/off the car alarm or open/close security house gates (well for that you need the key of the car alarm remote).

Grettings.

PD: Before someone say: "why yo don't do it?", i'm not have the enough skills to do that yet, i'm a noob.