Pope Benedict XVI has sent his first tweet to launch a Vatican news and information portal on the 60th anniversary of his ordination.
His message read: "Dear Friends, I just launched News.va Praised be our Lord Jesus Christ! With my prayers and blessings, Benedictus XVI."
The Pope, 84, tapped an iPad to activate the portal and send the tweet.
Twitter, Facebook and YouTube are all now being used by the Vatican to spread its Christian message.
Its Twitter account has more than 33,000 followers but "follows" nobody.
Images released by the Vatican showed the Roman Catholic leader seated at a table with officials standing by to help him use the tablet computer.
'News.va, The Vatican Today'
The launch took place on Tuesday GMT but was aimed to coincide with the feast day of St Peter and Paul on Wednesday, which is also the anniversary of Pope Benedict taking Holy Orders.
An article on the ordination led Wednesday's News.va news page, recalling how Joseph Ratzinger, then 24, was ordained on a "radiant summer day" along with 42 other young men.
Under a logo which reads "News.va, The Vatican Today", the new portal offers "an exclusive, multimedia presentation of all the other communications websites of the Holy See", including Vatican Radio, the newspaper l'Osservatore Romano and the Misna missionary news agency.
Pope Benedict's six-year papacy has been bedevilled by poor communications.
Embarrassing clarifications had to be issued over such thorny issues as his 2005 speech about Islam and violence, and his stance on condoms and HIV.
Earlier this month, the Vatican announced plans to set up a new e-learning centre to help safeguard children and victims of sexual abuse by clergy, as part of its efforts to deal with damaging scandals.
Last month the Pope issued new orders to bishops, making clear that any suspected abuse by priests must always be reported to police.
Reacting to the first papal tweet, some Twitter users joked about the iPad, asking if the Pope had a sponsorship deal.
A tweet from another user, Shanna Quinn in Chicago, read: "The pope is on twitter...this probably means my mom will be on twitter very soon."