YouTube has enabled HD viewing following the recent format change to a wider layout for videos. In case you're HD unaware, high def videos require a widescreen format for optimal viewing. That's why all the fancy pants LCD HD tvs are widescreen. YouTube was prepping for HD videos online with the format change.
Just click "watch in HD" under an HD-enabled video and it will automatically play in HD. You can also visit the new HD videos section to browse HD videos. If you need to prepare your videos for the new widescreen format, click here for the FAQ.
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