Finding ONLY playable videos in Google Video

Google Video is cool but I got tired of wading through all the non playable videos. After looking around a bit I found the query option to only find playable videos:

Just add playable:true to your search query and the result will be playable videos.

I submitted this tip to Livehacker.com and they posted it here: http://www.lifehacker.com/software/google-school/google-school-video-search-tricks-133613.php