I use a pair of LCD's on my desk at home and I've temporarily burned in the UI for a couple games after a marathon weekend. So far it's gone away over time. Screensaver wouldn't have helped though, since I was active on the monitor during the burn in. I used to use a plasma as my primary monitor, they are legend for burn in, had problems with that all the time and I used to change the aspect ratio on the set every hour or so just to try to keep it from happening.