The battery is running down extremely quickly. In four hours it is almost dead. What could be running to make it run down so fast?

Which Galaxy? I'm trying to get to the bottom of the same problem with my Galaxy Portal. Think I have it. Need a few hours to check ...

i have the samsung galaxy S (i9000)

Install advanced task killer from the market, see whats running and kill as much as you can.

Even so 4 hours seems ridiculously low. I wouldnt rule out the battery being defective.

I'm also finding the battery power to be poor on my i9000 and have to charge my phone every day! Also, I haven't been able to load any Youtube videos for the past 24 hours through the application - anyone else having that problem?

I phoned and explained about the battery running down so quickly and they are sending me a new battery. If that doesn't work they will do a full exchange on the phone.

I just loaded a youtube video as a test and it worked fine for me.