I still dont know why VZ employees at the store insist on having people load those... Anyway, here is what you are seeing.
*Disclaimer* the following is written so my wife can understand it, so things are a little simplified.
some terms you will need to understand put very simply:
Thread - an open application
process - the open application that is actually doing something
CPU - brain of the device that does all the thinking
What you see in the task killer is all the threads on the phone. The phone keeps the threads around so that those applications will open very quicly for you, and remember how you left them. When they are actually doing something, the thread will start up a process. Just because you see a thread does not mean there is a process running for it.
When you close out the thread (which verizon employees tend to say will help you conserve battery) your phone has to recreate the thread the next time you run it. this means that you may not have your previous state available, and it may take a little longer to open up than it would have.
What is the harm of an open thread? Nothing as long as there is no process, and the OS will manage what threads are stored in memory very well. After all Google had the user and the speed of an app in mind when developing the OS.
My recomendation... use an app like watchdog. It allows you to see what processes are running by monitoring the CPU to see what threads have a process using it. If it finds an app that is negativly impacting your phone it will alert you and you can then close that thread from the same screen. It is free on the market with the lite version, but if you can afford it, show the developer some love and purchase the full version. It comes with a nice little widget that allows you to see right on your screen just how hard your CPU is working. If it is in double digets you either just turned your phone on or have an app that needs to be shutdown.
