World Youth Day organisers are preparing for next year's event in Madrid with the help of Facebook, YouTube and Twitter.
Auxiliary Bishop Cesar Franco Martinez of Madrid, the general co-ordinator of the event in August, said social networking sites were key outlets "for raising awareness, mobilising, communicating and financing World Youth Day".
Bishop Franco and others spoke at a Vatican news conference on the preparations involved in next year's gathering.
Maria de Jaureguizar, vice director of communications for World Youth Day 2011, said: "It will be a WYD that is fully immersed in the internet, the place where young people today meet.
