Twitter is an online social networking and microblogging service that enables its users to send and read text-based posts of up to 140 characters, informally known as "tweets."

It has many applications for education as exemplified in the following useful links:

Scoilnet: Twitter in Education
The Ultimate Guide To Using Twitter In Education
Twitter: Presentation and Resources
Twitter in Education; how and why we should use Twitter in Higher Education
A guide to using Twitter for teachers
50 Ideas on Using Twitter for Education
An Educators Guide To Twitter
A Minimalist’s Guide to Using Twitter
Twitter Tutorial - Getting Started - YouTube (A simple step by step tutorial on how to create your Twitter Account, Add friends and Tweet Posts!)
The Twitter Hash Tag: What Is It and How Do You Use It?


Who to follow?

Some suggestions on who to follow:

NCTE: http://twitter.com/ncteireland

Scoilnet (Primary): http://twitter.com/ScoilnetPrimary

Scoilnet (Post-primary): http://twitter.com/ScoilnetPPrim

CESI: http://twitter.com/cesitweets

#edchatIE: A weekly discussion by Irish educators.
Summary of #edchatie Number 20, topic "Google+: The ideal social networking tool for education?" (PDF)