One of the most important things to remember with any smart phone is they are only as smart as the user. Touch screen devices do drain alot of power, but there are steps you can take to help maximize battery life.
The power control widget is your friend.
Wifi, bluetooth, GPS, extra applications running in the background and screen brightness all the way on full will always drain your battery an leave you feeling starved for juice in no time.
If you not in a situation where you need to use wi-fi.. turn it off. same with gps and bluetooth.
If your not outside in direct sunlight, there's no reason to have you screen brightness all the way on full.
Developers love making their applications run on system start. They are obsessive compulsive about it. This is true not only for smart phone but for regular pc's too. You would be surprised at how many applications are loaded at boot that you would typically not expect to. All of these processes require CPU usage and will take a toll on battery life. Download a task killer to keep this under control.
( I use Advanced Task Killer & included widget for 1 touch killing of all predefined apps)
And last but not least.. Rechargeable battery life always degrades over time on any device. This is caused by devices getting an artificial expectation of assumed battery power caused by charging and recharging of devices while at different battery levels. The device ends up thinking its empty or full when it really is not. Most manufacturers would recommend replacing the battery when this becomes an issue, but most of the time this is not necessary. You may easily recalibrate your battery yourself and save some money.
Drain your battery as totally as you can. When the device shuts itself off from lack of juice, turn it right back on again and keep doing so.
Then once it won't come on anymore, keep the device off, and plug it in and charge it for at least 8 hours.
Doing this is far better than nothing, but if you truly want to calibrate you battery to your best possible ability, you may use a device called a joule thief to totally drain the battery before putting it back in and recharging it. A joule thief will remove every last bit of power from a battery, much more than just powering on your phone until it wont come on anymore. Even when your phone wont come on anymore there is still quite a bit of power in your battery, just not enough to power on your device.
Just my 2 cents