There is some confusion as to what that “extra” attack is. It is one extra attack. Period. Not an extra full-attack. It is at your full BAB. You can make your extra attack at any time in the round. If there is some advantage to doing it after all the other attacks are done, you may do it last or first using any weapon you have available, but it is not an actual standard action. You cannot use it to make a move action. You cannot use it to draw a weapon, or scratch your ass. It is an extra attack, ONLY when you make a full attack action. If you are doing a standard and a move action, it then has the benefit of giving you 30 extra feet of movement, but you do not get an extra attack, no matter what you do with your standard action.