They look just like the panels on the show, although perhaps a little more glossy. The sliding switch on the speaker part lets you toggle between the Star Trek door 'whoosh' sound (up) and a red alert klaxon (down). The red light flashes when the red alert goes off. Pushing the white button makes the intercom sound.
Around the back of the comm panel are a two switches that control the volume and which motion detectors (one on each side) are active. The panel can be set to use either left or right detector, or both. 3 AA batteries power the unit. Two slots for screws let you mount it to the wall.
As far as I can tell, the white block doesn't light up at all, which is too bad. Would have been cool if it lit up when the button was pressed. I wonder how hard it would be to hack a light into it.
I think it's pretty cool.
Update: I decided to mount it next to my bedroom door. When I go to sleep I can set it to the red alert alarm and it will go off if someone tries to sneak into my room. Not that anybody ever does that.