Windows 7 includes flashy, high-resolution icons for almost everything—even the specific devices you have attached. Blogger Long Zheng figured out where those icons are stored, so you can use them elsewhere.
Most of the time, the Devices and Printers screen in Windows 7 will show you a giant, high-quality icon of the exact device you are using—Windows downloads those icons directly from Microsoft when you install a new device. Not every device has a custom icon, but most name-brand devices will probably eventually be supported.
To access the icons, open up an explorer window and paste %LOCALAPPDATA%MicrosoftDevice Metadatadmrccache into the address bar, and you should see a number of folders for each device. Within those folders you'll find the high-quality icon for each device, which you can copy somewhere else to use when creating shortcuts or pinning items to your favourite application launcher.
Long Zheng also has instructions for grabbing all of the generic device icons, and even explains that if you can hunt down the GUID for your device, you can download and extract the icons manually and use them in previous versions of Windows.
Admiring Windows 7's high-resolution device icons [istartedsomething]