From Justin Taylor @ http://theologica.blogspot.com Based on 1 Cor. 11:17-34 Professor Peter Gentry sees six major themes in the Lord's Supper:
1. Saving Sacrifice (This is my body)
2. Covenant (This is my blood)
3. Commemoration (Do this in remembrance of me)
4. Participation (Community)
5. Expectation (Future hope)
6. Proclamation (Evangelism)
Read the whole article; these are helpful themes to meditate upon as we gather to eat the bread and drink the cup.