You can always use a task managing-type of app. A lot of the apps in WM don't close even if you want them to, but of course the one you want to stay open will close everytime!!
MagicButton is a cool little app that you can minimize an app with, bring up a list and go back to app of choice, and other little goodies (and it's free):
http://www.trancreative.com/mb.aspx