Blue lines on LCD screen

Has anyone had random blue lines show up on your monitor that stretch all the way up and down? One appeared on my powerbook screen, but then dissappeared after awhile. No programs open, just straight up desktop. I have had friends who have had this happen also, but they didnt know what it was. Is it a sign that the LCD monitor is going out or bad pixels? My book is about 4 years old. Any suggestions or insight?

may be either your lcd, video card or logic board crapping out

I talked to my friend and she said that she had to "massage" the back of the screen to get them to go away, but after awhile they were permanent. Kind of interesting to have to do that, but I guess it will work for now.