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TwitterMSN is another bot friend brought to you by the creators of TwitterMail.
The premise is the same as its first product: access and update your Twitter from a third party service. Now you can send updates to your Twitter account from your MSN chat tool. You can also receive the most recent tweets from friends by sending "friends" to the TwitterMSN bot. As with TwitterMail, you can send posts longer than the 140-character limit, and a link will be provided at the end for viewers to read the rest of your message.
TwitterCal is another recently launched Twitter bot that lets you update your calendar from Twitter.