How do i edit a picture making it grey with one main color standing out?

Question: How do i edit a picture making it grey with one main color standing out!?

like this picture!.!.!.!.!.

http://media!.photobucket!.com/image/green!.!.!.Www@QuestionHome@Com

Best Answer - Chosen by Asker:

easy!. go to picnik!.com (free photo editing website)
go to edit
go to black and white
on this setting, you can use a paintbrush to either keep the original color (everything black and white except one thing, such as an eye) or make everything colored except one thing in black and white!.Www@QuestionHome@Com