It's Yahoo Answers again.

http://answers.yahoo.com/question/index?qid=20060923202508AAKhUd3

Someone asks:

How turn computer monitor into mirror?

It's a fair enough question. He or she may have seen the Dell commercial in which a webcam is used to turn a laptop into a mirror. However, to achieve this goal, the asker tried to scan a mirror and set the result as desktop background! Because (s)he received no satisfying answer, (s)he's now waiting for improved monitor technology to make it possible.

 That is either a troll post or conclusive proof that humanity is doomed to fail as a species.

this won't work. Mirrors work by reflection

Thank you.  I had no idea.

But the best answer was

try a really big hammer

 Actually there is a flatscreen TV out there that is a mirror when turned off... Can't remember who makes it, but can remember the blurb.

 Yeah but the guy wants to have his desktop image work as a mirror (so I guess he could still have icons and windows on top of it). For that you need some pretty advanced technology.

 Or if you want a half result you could just set it to black, turn off the lights in the room and put a spotlight on your face.

hvm:

 Or if you want a half result you could just set it to black, turn off the lights in the room and put a spotlight on your face.

...or simply use one of those glossy LCDs.

hvm:

 Yeah but the guy wants to have his desktop image work as a mirror (so I guess he could still have icons and windows on top of it). For that you need some pretty advanced technology.

By "advanced technology", I assume you mean "A webcam, and an OS that still supports Active Desktop".

The only barrier to making this happen is the fact it's a really stupid idea.   All the technology you need has been readily available for at least a decade.

A) Cover your screen with a thin layer of metal.  Set your desktop wallpaper to plain black.  Turn your screen brightness to maximum.  Turn on your room lights.  In areas where the screen is black the reflected light will dominate, acting as a mirror.  In areas where the screen is illuminated the transmitted light will dominate, acting like a highly glossy screen.

B) Write a bit of software to set the webcam image as your desktop (properly reversed).  The operating system might not be able to handle a full thirty frames per second, but even one frame per second would be neat.

C) He didn't say that he tried to scan a mirror.  He just said that scanning a mirror wouldn't work.  Maybe he didn't want a thousand answers from people with less physics knowledge suggesting to try just that.

 

What about those 'overlay mode' video displays, where the application sets a window to a certain shade of off-black and anything with that color gets painted with the appropriate video by the video card? I recall using that with WinAmp visualizations some years ago to make some awesome stuff go on behind my icons. If you could hook a webcam feed up to it, that could work nicely.

merreborn:

hvm:

 Yeah but the guy wants to have his desktop image work as a mirror (so I guess he could still have icons and windows on top of it). For that you need some pretty advanced technology.

By "advanced technology", I assume you mean "A webcam, and an OS that still supports Active Desktop".

The only barrier to making this happen is the fact it's a really stupid idea.   All the technology you need has been readily available for at least a decade.

Actually, all the technology you need has been around more-or-less since the 19th century.  Ok, they didn't have monitors back then, but they could produce the same effect with film or magic lantern.  You don't need anything as complex as a camera and display system, you just need a "Pepper's Ghost" arrangement.

Rycochet:

 Actually there is a flatscreen TV out there that is a mirror when turned off... Can't remember who makes it, but can remember the blurb.

Many, actually, google "mirror tv".

There's a Game Boy Advance homebrew program that turns the screen into a mirror. It simply turns it solid black.

DaveK:

Rycochet:

 Actually there is a flatscreen TV out there that is a mirror when turned off... Can't remember who makes it, but can remember the blurb.

Many, actually, google "mirror tv".

 

 

http://www.youtube.com/watch?v=d_9iEBvk_8Q

ummm... it's a mirror while the TV is on, too. 

 

"Great work marketing team! We now have a television that projects the ambient crap around the room even brighter than the actual image! People will buy anything if it's shiny..."

Rycochet:

 Actually there is a flatscreen TV out there that is a mirror when turned off... Can't remember who makes it, but can remember the blurb.

 

Reminds me of the LG Shine in a way.

Didn't you know?  Yahoo Answers is for people who are too stupid to use Google.