A couple of Deity quests.
You basically find the avatar of the Deity you want to follow (restrictions are imposed regarding good and evil) and do about 5 quests, the last one being a very tough lvl 70 one. Or relatively tough, depends on how you look at it.
The rewards are an altar you pray at and where you can sacrifice armour and weapons to gain points, which you use to buy 'miracles'. Low lvl ones aren't all that grand, but later on those miracles get to be very good. And the final reward is a cloak, of good quality too.
At least, this info is three months old, so no guarantees about the total accuracy at this point unfortunately!