One very practical way in which we can experience what the Week of Prayer for Christian Unity means is our annual pulpit exchange.
For anyone who doesn't know what it entails, minsters and lay preachers go to other churches, of a different denomination and preach at a regular Sunday Services. Some lead the whole service, others just preach a sermon. Each year it gets larger and there is great deal of planning involved ( thanks Jim ) to make sure that we don't end up with preachers going to a different church of their own denomination, or that they are not returning too soon to a church where they preach in previous years.
This exercise is an important one as it allows us to discover Unity through Diversity in different ways. The receiving congregations experience the preaching of another tradition and the visiting preacher experiences worship in the style of worship of another tradition. Even when the visitor is taking the whole service, there are lots of benefits. The preacher learns to work within a framework of a usual service for another tradition, and the receiving congregation will inevitably experience a different style of worship and worship leadership.
Please pray for all who are exchanging as they prepare what they are going to say.