Show the date and calendar on your Mac desktop with Dateline
Dateline is a nice little utility that places a transparent linear calendar on your Mac desktop. It’s pretty customizable so if you want the dates to be horizontal or vertical, or the text color or their background colors to be different it’s just an easy couple of tweaks away. Perhaps the best part about Dateline though is that it integrates with iCal, so double-clicking on a date will launch iCal and show you your calendar for that day. It’s free, it’s lightweight, and it requires Mac OS X 10.5 or newer.