Here's Chris with an important post on the Office as missing link. Here's Derek with an equally weighty one on the Office in the Roman Catholic Church, and pointing out a highly informative article on the Office.
Both very much worth reading. I resonate strongly with the idea of the Office, with its common thread of the praying of the psalms, as a much-underappreciated ecumenical link. True, non-Roman Catholics can't receive Communion in an RC church, but we can certainly pray the Office together if we're willing even to think of that option.