There is lots more about Invocation 2011 at the website here , including a wonderful sermon, given during the final Mass of Invocation 2011, by Archbishop Antonio Mennini the Apostolic Nuncio to Great Britain.
Here's a little of what the Archbishop said:
In time we discover that the longing within us cannot be fulfilled by what we accumulate, experience, or by the power we wield. If we want happiness we must resist the temptation to act in ways that will alienate us from God and from our neighbour. Without God something will always be lacking. This was the experience of St Augustine who in his youth looked for excitement in external pleasures. It was only when he found that he remained unsatisfied and started to look within that he was able to recognise the presence of God and so discover true happiness and deep joy.
Never forget too, that when God calls us by name and asks us to follow him, he offers us true freedom, which is not just a freedom from..important though that be. Rather we are being offered a positive freedom and loved and trusted enough to be his workers in the world. God asks us, in the face of all that seems wrong in our world, to be positive, to build up his Kingdom and to change the world for the better. There is no place for pessimism here, for his call to each one of us is, in fact, liberation.