Here is a list of Easter Eggs in the game. Enjoy (the work of someone who goes by the name of Ecurevil...):

- After defeating an enemy, press A without moving and Link will perform the cool-looking flourish move(spinning his sword before sheathing it) like he does in cutscenes. This may only work on harder enemies.

- On Epona, press A to get the speed boost then draw your sword, Link will hold it above his head like he's going in to battle.

- When going in to a group of enemies on Epona, you can do a quick dismount, and Link will hop off with a backflip. Similarly, if you mount Epona while running from the back, Link will hop up and speed off.

- You can talk to Epona when you're beast Link. She tells you to hurry up and change in to your human form.

- The night sky is an accurate representation of the real night sky. Stars are the correct brightness, and constellations such as Orion and Cassiopeia. The moon moves, but the stars stay still, however.

- Hyrule in this game is geographically very similar to Ocarina of Time. (flipped horizontally for the Wii version, as we know)

- The howling stone songs are all from Ocarina of Time. One of the Howling Stone songs is the Requiem of Spirit. Another one is the Song of Healing. Another is Oath to Order.

- Oocca are inspired by M.C. Escher's painting "Other World":

 

- You can find a silver rupee in the Cave of Ordeals, it's in the room with two Dark Nuts (about floor #39). Use the wolfs sense and dig for it. There is also a silver rupee in the bell in Kakariko village, you can clawshot it, or shoot it with bomb arrows, and there's one more in a chest towards the end of the game.

- In Agithas castle, you can kick pill bugs. Turn on your lantern, and the bugs will be attracted to it. Also Agitha will get frustrated if you leave her castle without giving her a new bug. Agitha can also be found outside the southern entrance of Castle Town, looking for bugs in the grass.

- If you go back to Diababa's lair a second time, there's a bottomless pit of water.

- In the fishing hole, Hena has a picture of the fishing pond owner from Ocarina of Time. If you quickly look over at Hena after looking at the Legendary Fisherman from OOT, she will be scratching her back. If you talk to her when she scratches, she makes a comment about it. In OOT, the Fisherman always was scratching his back.

- You can grow pumpkins by pouring water on them, which improves the items they give. You can also pour water on certain people for a reaction. These appear to be the only use of bottled water in the game.

- On the way to the first dungeon, you can steal lantern oil and red potions from the bird. If you run off without paying, the bird will attack you next time and call you a thief. This is a reference to Link's Awakening.

- When you open doors in a dungeon, Link opens them himself for the first time in a Zelda game. Dirt will fall off of the door the first time, but will be clean all times after that. Nice attention to detail..

- Ooccoo is the little bird that warps you out of dungeons. 00CC00 is the hexadecimal color code for the green of Links tunic in the original Zelda.

- Fyer (the cannon guy) has a bullet bill on his sleeve.

- The Ordon Shield is a one of a kind item, you can buy a replacement at Malo Mart, but it's slightly different.

- There's a rumour that if a blue chu and a yellow chu run together, they will form a green chu. Green chu's likely existed to refil the magic meter, a feature that was eventually dropped from the game. The magic meter can still be seen in a screenshot on the back of the box.

- When you ask the fortune teller in Hyrule Castle town for your 'love' fortune, her chant is actually "Wait....loading takes a while" spelled backwards.

- If you go in to Castle town as a wolf, the guards will circle you, if you charge the Midna attack and spin, they will get scared and drop items and rupees.

- In the Kakariko bomb shop there are signs that tell you not to bring in any flammable items. If you take out your lantern, the shopkeep will tell you off. If you take the lantern out upstairs, he will bang his desk and drop water on you.

- The postman can be found at various places in the game, but he's quite rare. He can be seen at several locations, including Kakariki village, Zora's Domain and even the Cave of Ordeals.

- Killing all Guays in certain areas will cause yellow and blue rupees to fall from the sky and trees.

- Links hawk can be seen flying around in any areas where there's hawkgrass.

- Fire a bomb arrow in to the sky for an instant firework!

- Sometimes, Midna hums her own musical theme. You can hear this when entering Twilight Faron Woods for the first time, for example.
 
- Talo and Malo's names are references to Talon and Malon of OoT/TMC

- The names of the provinces contain the names of the Godesses and the three girls outside the STAR game are also references to them.

- Try using the fishing rod on Gannon in the final battle. He become distracted, looking at the hook with a sort of "What are you doing?"

- You can also use a bottle against the last boss' first phase instead of the sword, as a reference to Zelda: A link to the past and Zelda: Ocarina of Time, where you could use the bug-catching-net or a bottle to bounce Ganon's fire.

- The triforce symbol on Link's hand is inspired by Havelock the Dane, in which he has a radiating light and a cross symbol indicating that he was divinely ordained for kingship.

- The light and dark worlds were likely inspired by the dual worlds of Orpheus.

- Orpheus is also a hero because of his instrument, which may have been the evolution of the use of the Orpheus story in Ocarina of Time.

- When you catch a greengill, they refer to these fish as "small fries" which is what the painting fish in Wind Waker would call young Link all the time.

- If you attack a chicken enough times, you become the chicken for a few seconds... you can run around and jump. This works both as regular link as well as in wolf form.

- The Goron that sells things on that balcony in Castle Town says "It's a secret to everyone" to you at some point.

Source: IGN Boards