The integrated PowerShell ISE editor has its own icon and can be pinned to the Windows 7 taskbar, just like PowerShell. Try this:
Open PowerShell, and launch ise:
(If ISE does not start, you may be working on a server. ISE is not installed by default on Windows Server. You will first have to enable that optional feature).
ISE starts and displays its own icon in the taskbar. Right-click it, then choose "Pin this program to taskbar". Next, move the pinned icon to the left, so it is placed adjacent to your PowerShell icon. Done! Next time you need the editor, simply click your new persistent taskbar icon.