MobileSafari, MobileMail, MobilePhone, all running in the background. fairplayd is the fairplay daemon, commcenter manages communications (all of them), springboard is the desktop, lockdownd is the little thing that checks to make sure the phone is activated (and locks it down if not)

only the top three apps (bash, top, sshd) aren't there on a vanilla iPhone. Apple's apps will run in the background, but other (app store) apps exit completely when you return to the home screen.

Apple could easily write a specialized API that lets you run virtualized background processes. This would be an improvement on the current situation, but it would maintain heightened security.