Has anyone here experienced 'burn in' on LCD displays?

I noticed some recently on my Dell U2410 monitor. I frequently have a browser window open and an IRC window open, and the edge of the browser window seems to have caused a noticeable permanent line. It wouldn't really be noticeable with a photo as a desktop background, but I had 'Windows 2000 Blue' as my background for a good few months this year, and it was noticeable with that. To fix it, I rearranged my windows for a few weeks and it seems fine now.

I've noticed LCD burn in more frequently on public LCDs. Until a year or two ago, our local bank had an outdoor ATM with a nice green CRT. They replaced it with a modern LCD variant, and after not very long the 'FREE CASH WITHDRAWALS' stays visible even when the screen changes.