Hey guys. I was just curious if I can leave my 20D in the on position for long periods of time knowing the camera will shut off because of the powersave...or does the battery drain a bit more when its on like that?
You should probably define "long periods of time". When I'm shooting all day, I leave my RebelXT on all day and simply half-depress the button when I want it to wake back up. I haven't noticed any significant problems except on really long days - which is why I always carry at least one extra battery fully charged.
On the other hand, if you're intending to leave it that way for weeks or months, it's probably better to turn it off because that way all of the systems will have shut down elegantly rather than having their power simply drain off to nothing and choke your circuits.
The battery DOES drain more when the camera is sleeping than when it's off.