The Flute and Fast Travel
The Flute in A Link to the Past is one of the most useful items you can acquire as it allows the player to fast travel to a few specific locations on the map. Getting the Flute as easy as possible in the game will save you hours of running around from place to place. It's strongly recommended you do this side quest very shortly after visiting the Dark World.
To get started what you'll want to do is head over to the Dark World and to the location where you see me standing at in the pictures above. There will be a little creature you can talk to on the stump here that will tell you about having buried a Flute nearby and he'll ask you if you'd find it for him.
He'll hand you a Shovel which you should take with you back to the Light World. He buried the Flute in this small opening in the forest so dig around to find it! Or use my picture below for the exact location to dig.
Funny that this 'Flute' looks almost exactly like the Ocarina of Time from the N64 Zelda - huh? Once you have the Ocarina of Time - err - Flute return to the Dark World and try to return it to the creature on the stump. He'll tell you his days are numbered and all he wants is to hear the Flute being played one last time.
Out of no where, Link suddenly learns how to play an instrument and gives a nice tune for the creature who transforms into a tree. With the Flute in hand our next stop is Kakariko Village, specifically the statue of a Weathercock nearby the Magic Bottle salesman. Stand in front of the Weathercock like where I am at in the picture below and play!
The statue will break apart and a bird will fly out of it and away. You may be thinking... well that was pointless... but I assure you it was not! Play your Flute again and the bird will come back and whisk you away. A new screen will pop up with a few different numbered locations on them (as seen in the screenshot below).
As long as you are standing in the Light World you can play the Flute anywhere outside and the bird will come to you and it'll bring up the fast travel menu found below.