to hatch an egg i think you need to walk around for a distance for each Pokemon its different here is a link :) http://www.Google.co.UK/URL?q=http://Pokemon.marriland.com/diamond_pearl/pokedex/list/sinnohdex/&sa=X&ei=5mQ4TLi6O8L9nAfs_43gAg&ved=0CBkQqwMoADAA&usg=AFQjCNHp-3Y_lOEeiHF3VBephWSNpQ4nPg
you can't hatch a pikachu egg on diamond, it hatches in to a pichu.
you run around sinnoh and it will hatch.
run around
Yes
It takes about 2805-3060 steps for an azurill egg to hatch.
you walk around for ages and ages and it will eventually hatch
You have to have the egg with you and walk several thousand steps.
It takes 9,180 steps or 36 Egg Cycles to hatch an Eevee.
in order to hatch a riolu egg you need to walk about 5,000-6,000 steps
The best way to hatch an egg in diamond version is to use your bike, because as you know, the egg will get closer to hatching if you walk more, and riding your bike counts as walking.
Just randomly ride around like with any other egg. After you have taken enough steps the egg will hatch. It will take 10k-10.5k steps to hatch it
it takes about 2500