TwitCal is a simple online calendar you can update via Twitter.
You can add events to your diary through TwitCal or your favourite Twitter client.
To add an entry into TwitCal, just send a tweet including the dd/mm/yy format, like this
(dots, dashes or slashes accepted) '20/11/09 This will be your calendar entry' or using an abbreviated 3-letter month name and numbered day, like this
'Nov 20 2009 This will be your calendar entry' or the full month name and '1st', '2nd', '3rd' or '4th' suffix on the day number, like this
'November 20th 2009 This will be your calendar entry'.
To then view your calendar simply visit www.twitcal.com and look up your username.