[online@The Providence Journal]

ORONO, Maine (AP) -- Twitter, the online social networking service that's become popular with celebrities and politicians, is linking second-grade classes in two Maine towns.

Mrs. White's class in Orono has been Twittering for about a month with Mr. Thompson's class in Greene, exchanging messages that can't exceed 140 characters.

Debbie White said she decided to bring the micro-blogging site to her classroom to help her pupils learn writing skills by composing messages, known as Tweets.

Most of the students seem to be enjoying the exercise. Some say it's like having pen pals online.