You run or bike around.
You have to walk around with it. It will hatch faster if you have a Pokemon with the ability Flame Body.
you run around sinnoh and it will hatch.
pure luck
no
you need to hatch a togepi in soulsilver or heartgold then trade it to pokemon diamond
run around
Yes
you walk around for ages and ages and it will eventually hatch
in Oreburgh city in the museum
you can't hatch a pikachu egg on diamond, it hatches in to a pichu.
I don't think there is!
It depends on the Pokemon you are hatching.