65+ Online Calendars and Calendar Tools: "Many of us prefer to manage our appointments, social events, and to-do lists with online calendars. The list below contains over 65 calendars, tools & resources, which should be a good starting point for all your online calendar needs."
Have to admit I do just use the Google Calendar as it's simple, portable, accessible and share-able. But since my time management leaves a lot to be desired, keeping these for future reference can't be a bad thing! Especially when it comes to New Year's resolutions and the eternal desire to see if I can't do things just a little bit more efficiently.