J,
The primary function of this app is to completely block the phone with regard to the apps of your choice. The reason why I said if you have the time is that what you would have to do is create your white or black list, add or delete apps, and check over the course of a day or so to see how your battery life results with various apps shut down from data. Obviously this will not show you if you have a runaway app with regard to internal memory, but you can now check particular apps to see if they have a runaway data situation.
The approach I have taken is to use a white list (allow) and uncheck every app that is not a core function for me. In my case I have email, gmail, google voice and a few other core components with allowed access. Then what I have been doing is using my other programs, noting which ones give me any errors upon use. For example, maps or browser will give you a network connection error. This is obvious.
What are not so obvious are apps with adds, or perhaps apps that might be doing something with data in the background. If you recall back to when you install an app, it lists what services it will need. Many will say network connections, but do you really want your text editing app or other strictly on phone app to have network resources?
This is not an easy way, but again Droidwall was designed for security, and it is my belief that you can also use it to control other aspects of the phone, and how they could affect your battery. You could also just shut data down, but then you have no email or gmail, or perhaps market updates. This way you can isolate each app, without sacrificing core app accessibility. And the program has a widget which is a toggle on and off, for ease of implementation.
Craig
^ GREAT STUFF and thx for the timely response. I was messing around with it today a little but not too much but I will do my own testing t osee what type of results I can acheive. I was using my phone today with data/3G turned off but as you simply stated, my phone did feel isolated. Like it was being held back. No MMS messages could be sent nor received, no emails, etc. So I will do further testing for 'Droidwall'. Thx again!