She is from UK

Not a hope !

For all practical purposes, you can't.
There is facial recognition software, huge computing requirements, and you need access to databases of pictures that you won't be able to get.

Or if you use Facebook you could put her photo up on it and tell everyone you looking for her, or make on of them group things on it and people that arnt even your friend will see it if they join :D it's a long shot but its all I can think of

I want to find this lovely boy I saw. I didn't catch his name, but I have a picture of him and a lot of other people. How can I find him, I really want to find him. Please help

I met a Lady at Istanbul Airport in July 2011, I got only her photo, nothing else. How can I find her, she lives in Kuwait.
Please help me in this issue