[AT&T Samsung Galaxy Note I717] littlewierdo:
Battery usage could be anything ranging from app(s) to radios to screen time to battery calibration.

I stream via bluetooth podcasts and audiobooks for 9 hours a night, turning on the screen once in awhile to do a google search for something, doing a market search and possibly installing an app, or long enough to pause playback for times I need to get out of the truck for bio-breaks and I end the night somewhere between 60-70% battery life LEFT on my phone. But I try to keep my phone call and screen usage down as these two are the biggest battery drains that I have seen.

If you can afford to spend a little money, buy an app on the market called Battery Monitor Widget Pro by 3C (look at the screenshots to get an idea of how informative this little app is). This little app will tell you pretty much anything that is killing the battery in a very easy to read way, otherwise, its troubleshooting time.

With regards to apps, the one thing I learned a long time ago with Android is, if you dont need / use it, uninstall it. My Note is pretty lean with only about 15 user apps and nearly all of the ATT bloatware removed.

You can also use Autostarts if you have root (open Autostarts and hit menu, then sort by apps) to manage apps start and stop time. Be aggressive with user apps. Unless the app has a reason to run in the background, use Autostarts to disable EVERY condition that a particular app might start under (again, DONT do this for system apps, do this for USER apps ie, apps that are coloured white). For example, Google Maps has absolutely NO reason to be running in the background so disable every condition it starts under. However, something like Beautiful Widgets DOES need to run in the background in order to update the weather and update the widget. In general, if an app has a widget YOU USE or is scheduled to perform a task at specified time(s) during the day (a podcast client for example that automatically downloads new episodes) or needs to be running to perform a task when certain events happen (Easy Call Filter for blacklisting incoming phone calls), leave it alone. If it doesnt meet any of these conditions, disable all of the conditions for the app running automatically. And if you never use the app, uninstall it.

Alternatively, on a day where you dont need your phone as much, backup your apps and do a factory reset (Settings, About Phone, Reset Phone) and let it run stock for a few hours and see what your battery life is without apps. This might help you determine whether its the battery or an app that is causing a problem.

The radios on the Note seem to be pretty battery conservative with exception to phone calls. When I am on the phone, this KILLs the battery very quickly (regardless of whether the call is going to a bluetooth headset or to the handset speakerphone or the headset ear speaker. I guess not much else that can be done here. I did alot of testing here however and cellular data, wifi, gps, and bluetooth use very little battery power.

The screen is also a big drain (much higher on the Note than it is on the Captivate). Make sure that your screen isnt 'turning on' unless YOU turn it on. A few apps (BeyondPod for example) have the ability when they are doing anything over wifi to turn on and keep the screen on during the duration of the wifi network access. This is a feature only required for older Android OS's. Google added a Wifi sleep policy to Eclair (Settings, Wireless and Network, Wifi Settings, Menu button, Advanced, Wifi Sleep Policy, set this to Never) and so now the system never turns off Wifi.

Last is battery calibration. This likely isnt the problem, Ive played with this a number of times and it never has benefited me much. The easiest way to calibrate the battery is the following (the entire process takes less than 5 minutes).

Plug the phone in with the phone on and let the battery fully charge (get a battery widget if you need to see percentages).

Unplug the phone and power the phone down.

Plug in the charger and let the battery fully charge (use the volume keys to turn the display on so you can see the battery indicator).

Unplug the phone and boot the phone, wait for everything to stabilize and then power down the phone.

Plug in the charger and let the battery fully charge (use the volume keys to turn the display on so you can see the battery indicator).

Unplug the phone and boot the phone.

This process only need be done ONCE when you either flash a new rom OR get a bigger battery.

This btw is not 'boost' charging, nor is it bad for the battery if done once in awhile (no more than once a week). Its just a fast method of letting Android see what the battery level is when it is fully charged which will allow the battery to charge to near its maximum when the phone is on and plugged in (for some reason, out of the box, every Android phone I have seen only charged to about 93-95% of the batteries capable charge level and it should be charging to 99% of the batteries capable charge).

Anyways, this was a long post, not much else I can suggest to help with battery. The radios are not the problem with this particular phone, the screen time is going to be the same drain between all of us so the only other thing I can think of is battery calibration or what apps you are running and my guess is, its an app (like I said, a factory reset and running the phone stock with nothing extra installed for awhile might help determine if its an app causing your problem).