Windows only: Free application DateInTray adds a small, unobtrusive calendar icon to your system tray displaying the current date. Clicking the icon displays a small pop-up calendar. If you liked the calendar integration of previously mentioned Analogue Clock but don't want to expand your taskbar to enjoy it, DateInTrayis a perfect utility. And if you're the type to avoid extra system tray utilities to avoid bloat, DateInTray's minuscule 500-700KB of RAM usage should please even the most miserly of systems. DateInTray is freeware, Windows only. Thanks Doug!