Adjust bit rate on movie replay

When I go to YouTube to view videos on my PB G4, I can adjust the streaming bit rate from 480 to 360 to 240. I need to play at 240 on my unit in order to keep the video clip streaming without halting, probably due to my limited RAM capacity of 1.25 mb.

When I view videos on other sites, I cannot find a bit rate adjustment in the video box, and most of the time, the video playback is halting and stuttering. Is it possible to adjust the bit rate on my computer screen another way?

Thank you