While you all are discussing VoIP , SIP , and the 2006 OS, I have been hopelessly wondering about how the 770 figures out it is in the closed position. What sensor(s) is it using, either mechanical, light based, magnetic?

Hope I am not the only one at night figuring out how the refrigerator door light works...

Not a dumb question by any means. I spent hours just trying to figure it out. Its a magnet. The sensor is located in the lower left corner of the device, just south of the home button. Place a paperclip against the corresponding area on the cover and it will stick. Similarly, place a magnet over the sensor area and the 770 will go into standby. Hope this helps!

Are you sure? Mightn't it not be the little switch
center-bottom of the screen? Not the spring mounted
nubbie inside the cover that seemingly pushs the
switch with the unit is slid into place.

Yes, s/he's sure. Try it yourself: take a fridge magnet and hold it directly over the HOME button (or just very slightly below it). Depending on the strength of the magnet, you might have to press it right up against the case, or you might be able to just wave it over the area. You can spend hours--okay, 30 seconds--amusing yourself by making the light come on and off.

Yeah, I'm sure. Try the magnet thing right below the home key. You'll see what I mean. Also, I don't believe there is a switch at the bottom of the screen. I think it's just a retaining bump.

If you had taken as much time to search through the forum as you spent posting the initial question, then doubting the answers you received with "are you sure ?", you would have found that this bit of knowledge has been all over the ITT forum for, at the very least, six months...