I'm not sure . . . what is a 'Twitter'?

Twitter is a social networking and micro-blogging service. It enables its users to send and read other users' updates (known as tweets), which are text-based posts of up to 140 characters in length. Updates are displayed on the user's profile page and delivered to other users who have signed up to receive them.

http://en.wikipedia.org/wiki/Twitter

How do I join Twitter?

Simply go to Twitter.com and sign up for your free account. Fill in a few fields and you're ready to go. 

Is that it?

Almost - while you're there make sure to 'Follow' us "ICPDat15" and you'll receive tweets of all of our updates! 

What else is there to know? 

You can receive and make tweets on a variety of devices including iPhones, Blackberrys, and most Nokia cellphones.