If you have pinned PowerShell to your taskbar (on Windows 7: launch PowerShell, right-click its icon in the task bar, choose "Pin this program to taskbar"), then a click on the icon will open PowerShell. Here are three neat tricks:
First, move the pinned PowerShell icon with your mouse to the leftmost position in your taskbar. Yes, icons are movable! Now, press WIN+1. PowerShell will launch or jump into the foreground, just as if you had clicked the PowerShell icon.
Next, press SHIFT+WIN+1 (or hold SHIFT while you click your PowerShell icon). You get a new PowerShell window.
Finally, hold CTRL+SHIFT+WIN+1 (watch your fingers). This time, PowerShell starts elevated (provided Windows uses UAC).
As you may have guessed, the number reflects the icon position, so pressing a "2" instead of a "1" applies your keyboard magic to the second icon in your taskbar.