Windows 7 Gadgets
Windows 7 Gadgets are the little apps that appear in the Windows 7 sidebar. To install on of my gadgets you need to unzip it to %localappdata%\Microsoft\Windows Sidebar\Gadgets\ after which if you right click on your desktop and select the Gadgets menu item, you can choose the gadget from the selection offered.
I made a binary clock in delphi once, but that was a plain old application. This is a Windows Gadget. The top row shows the hour, the middle the minute and the bottom the second.