Android show various things in the notification bar. Stuff on the left are apps you have currently running, and will (normally) show up in the notification panel under "ongoing". You can't move them to the right side. The icons on the right are set, system icons. You can hack certain things with root, though, to modify how the system ones act. For example, you can modify the battery icon set to display the battery percentage. Doing so requires root, as it is modifying framework files. It has nothing to do with market apps. It's actually modifying the system.