Actual code for posts:

<a title="Click to play video" href="javascript:void(0);" onclick="window.open('http://www.youtube.com/v/80uXr2kliDY', 'sickg', 'left=120, top=120, width=422, height=360, toolbar=0, resizable=1')"><img src="http://path to image" alt="Click to play video" /></a>


Actual youtube code:

<object width="425" height="353"><param name="movie" value="http://www.youtube.com/v/80uXr2kliDY"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/80uXr2kliDY" type="application/x-shockwave-flash" wmode="transparent" width="425" height="353"></embed></object>

Only this url b:

http://www.youtube.com/v/80uXr2kliDY

Cut und paste this line:

window.open('http://www.youtube.com/v/80uXr2kliDY

<a title="Click to play video" href="javascript:void(0);" onclick="window.open('http://PATH OF YOU TUBE', 'sickg', 'left=120, top=120, width=422, height=360, toolbar=0, resizable=1')"><img src="http://PATH OF IMAGE" alt="Click to play video" /></a>




Our video will be in new window.
As you can see in the above code I use only the YouTube permalink, not the whole embed code, which makes the video resizable (open it and resize it).