Some applications appear not to have an easy "off" button. So I kill them with the phone hang-up key. BUT, I think they're still there in the background. If I bring up the application switcher, there are lots of apps I haven't used in a while, all still there. Then I have to find a way to kill them one at a time, each with it's own archane key combination or on-screen button to turn them off.

1. Am I correct these are still in the background after I push the red phone (hang-up) key?

2. Am I correct they are sucking down memory while running?

3. Is there a universal, easy way to kill an application? Not that it's difficult, but to remember to press blackberry key, scroll down to the bottom, and push close seems to be a lot of keystrokes. And to push blackberry key, scroll down to application switcher, select the applications one by one, then blackberry-scroll down-Close is just awkward.

blackberry-scroll down-Close is just awkward, but it's the only sure-fire way, short of a battery pull.

And yes, in all likelyhood most apps are "sucking down" your memory while running. BB's have a rather limited amount of application memory available.

Wirelessly posted (Tmo's cheapest BB customer)

Just close the app whenever you're done with it and then it won't be so bad to close them down one-by-one from the app switcher.

The back button when held down for a couple of seconds will usually EXIT most applications.
The end call button, puts them to background, eating memory.