Open the inventory or press F5.
Chat with our AI personalities
Press f5
Press E or the button you set to look at your inventory, and you should be standing in a box.
Press f5 to go to 3'd person, press it again to look at yourself, and press it again to go back to 1'st person. (as of minecraft 1.1 ^.^)
press F5
Have a look at Minecraft Forums it should tell you, or you can go to Minecraft.net or Minecraft Wiki.