Twitter is celebrating its 5th birthday today. And to mark the Twitterversary, ABC’s “Good Morning America” co-anchor Robin Roberts becomes the last network TV news anchor on the planet* to sign up. @RobinRoberts sent her first Tweet this morning at 7:48amET, during GMA… complete with misspelling.

i.m finally here! Joining Twitter in hnor of you. My way of saying thanks for all your love and support for@GMA.

By they way, she’s about to crack 20,000 followers. Look out @bwilliams.

*We think