Both probably drain the battery. 3G phones are notorious for bad battery life. If you have apps that you are not using, close them. More charging devices or larger batter might help as well. I have charging pods at work and home as well as a car charger.
I don't find 3G a big deal when it comes to battery drain. I still get 18hrs+ with moderate use on a single charge. I charge my Bold every night anyway. Oh, and my phone is permanently on 3G.
