Odysseus offers the Cyclops three bags of wine.  The Cyclops drinks the wine without thinking of the possible repercussions of this and passes out.  This directly allows Odysseus and his men to blind the Cyclops after he passes out.  Prior to this, Odysseus tells the Cyclops that his name is "Nohbody".  This works out perfectly later in the story after Odysseus and his men sharpen a tree branch and stab the Cyclops in the eye.  When this happens, the Cyclops tells the other cyclops that "Nobody" hurt him after Odysseus and his men stabbed and blinded him.