I've got a 19" Samsung LCD monitor. At the top of the screen, a few pencil, etch-a-sketch lines have recently started appearing. Always the same lines in the same place. The cursor moves behind the lines. Any ideas on what caused this, and more importantly, how to get rid of it?

What is your monitor set to in Windows? If it's set to Plug and Play Monitor, that standard was designed for mostly CRT monitors when the first XP version came out, and I doubt that it has been upgraded in newer Windows versions. LCD monitors are not designed to use some of the settings provided by Plug and Play Monitor that CRT monitors can do, particularly high vertical refresh rates and high resolutions - if the LCD monitor does manage to display modes it was not designed for, you are more likely to damage the monitor by doing so. Load the drivers that came with the monitor - by default Windows will only show you the settings that both the LCD monitor model and your video card will support properly, and none of those settings will damage the monitor. If you do have the proper monitor drivers loaded, or if you are using more modest Plug and Play Monitor settings, then it sounds like you may have physical damage. Take a look at where the lines are from an angle off to the side of the screen, both when the monitor is on and off - does the screen look like something was pressed against the areas where the lines are? If you see no physical marks has this monitor ever been dropped, or could something have come into contact with its screen? Damaged or faulty circuits would usually cause one or more whole horizontal line to be dark or a different color. In any case, there is nothing you can do about the lines. If the monitor is still under warranty, you may be able to make a claim and get it replaced if no physical. damage can be seen.