I know this question is old, but for others stumbling over it:
Autostarts is an application that can disable apps from starting at boot time. It's the best I've found to do that (it isn't resident and doesn't kill processes like a task manager, it actually parses apk packages and reads registered actions and blocks the actions you tell it to). BUT it needs root and hasn't been updated for a while (december 2011). It works on Android 2.3 on which I tested it. Because it was discontinued, I don't know if it works on newer OS versions.
It's commercial now, but that's not the point, you need a peek at the source code.
If you search a bit, you'll be able to find the source code for an older version and see how it implements the blocking system.
I would be very interested in an application that could block certain services. NOT kill, but prevent them from starting in the first place. And the list is quite big: Facebook (OrcaService, MqttPushService, MediaUploadService, BackgroundDetectionService), Twitter, Maps (NetworkInitiatedService), Yahoo Mail Sync, etc. I don't use the features that the services provide, I even disabled some of them in the app interface where possible, but they still pop up and remain resident after exiting the application.