DeskDate is a cool utility used every day. You can quickly access a calendar and navigate to find or mark a date. Furthermore its look is very nice and you can customize it.

Features:
-Modern look
-Stays "on bottom"
-Customizable colors
-Customizable number of displayed months
-Easy calendar navigation (buttons, specially designed color menus, keys)
-Can start automatically after user login
-Localized
-User preferences saved in registry