The week between the feasts of the Confession of Saint Peter and the Conversion of Saint Paul is observed as a Week of Prayer for Christian Unity. These dates were proposed by the Revd Fr Paul Wattson (founder of the Franciscan Friars of the Atonement and a pioneer in the cause of Christian unity) in 1908. The website for the Pontifical Council for Christian Unity notes that these dates are observed in the northern hemisphere, while in the southern hemisphere a week of prayer for Christian unity is often observed around Pentecost (as suggested by the Faith and Order Movement in 1926).
The website of the Pontifical Council has materials for observing the Week of Prayer for 2008.
For each day of the week, I will be posting intentions for intercession. I have lifted these from the Daily Prayer, Supplemental Liturgical Resource 5 (1987), published by the Office of Worship of the Presbyterian Church (USA) and the Cumberland Presbyterian Church.
Today let us pray for the Church of Jesus Christ in every land, and for the power of the Holy Spirit in the Church.