I just noticed that playing YouTube Video in Safari or Google Chrome the CPU usage is not less than 70-75 % on both cores ( MacBook 2.4ghz unibody with SL 10A432 32bit kernel ). On Firefox the CPU usage on the same YouTube video is no more than 40-45% on both cores. Anyone else notice this ? I guess it may happen because flash plugin is 32 bit and used in some sort of sandbox in Safari now because Safari is 64bit and flash plugin is 32 bit ( in Chrome everything run in sanbox and I got the same CPU usage on Leopard ). Firefox is 32 bit application as Flash is and I'm guessing thats why it uses less CPU.