I have the same situation on my first week with the phone. the battery seems to drain so fast.
1. Turn off the wifi, GPS, bluetooth, background data. turn this on as needed. use the power control widget to ease your way on turning on and off.
2. Turn off data traffic. I observed that connecting to 3G/G greatly drains the battery you can even notice the back portion of the MP where the battery lies becomes warm with extensive use. specially, if there is apps running on background an tries to connect to the net. use the widget data traffic to enable and disable this. Turn on as necessary.
3. turn off auto updates, this goes with the data traffic. if the data traffic is off auto update will be blocked. some apps have auto update like timescape. you may choose the option to manual or set it to a longer period.
4. turn off auto sync, this can be found on the settings. these uses data. you can manually sync it anyway.
5. download the advanced task killer app, these kills the apps the keep running on background. choose only the apps the you need for everyday usage. It will save you some juice.
6. observe your downloaded apps. some apps keep running on your background and drains your battery.
7. Manage the brightness. when the screen is on it consumes battery. reducing the brightness will help. reduce the time to sleep mode.
MP being a smart phone, have so much to give... it is being limited only by its battery life from what i have observed. I hope there there are improvements in the battery life when the update comes.
cheers!