Why is Galaxy S keep getting drained off it's power?

You can avoid this by downloading an advance task killer from the android market. Set it to every 30 mins kill off all applications and free up memory. Remember you must also disable the "allow background data" options from the settings. Avoid using applications that has Ads. Lower down your screen brightness. You might also want to download "APNdroid" from the android market. This is a very useful app that allows you to toggle between non gprs and gprs data xfer mode.