If clairvoyance can do the same job? Any other reason than the fact that it fulfills the LOS requirment and clairvoyance doesn't?

Do you really need another reason!? LOS means that you can cast spells at targets you see using the X-Ray vision spell - you can manabolt someone who is in a room behind a wall, while the target of your spell can't even see you at all to retaliate. Actually, that's extremely powerful - cheesy, even. Probably why it didn't make it into Third Edition.

I was just curious if anyone used it for anything else.

You mean like this?

http://ecoustics-cnet.com.com/Peeping+Tom+..._3-5425105.html

Cool. I wanna try that out! (You know, for *scientific* reasons)

Heh, not quite what I had in mind, but funny nontheless. I actually read a while ago on the net about these guys who sell "X-Ray Vision Goggles" that work on the same principles as the camera in that article.

Gawd, not the X-ray camera gimmick again. Sony tried this same rumor trick once to sell more of their TRV video camera line when sales slumped back in '94 or '95.