Well guys this idea was rejected by bow, so
So this is a plugin were you can get xp from mining ores.
here is the link:
EDIT: I cant post links because im not 7 days old on here so just go to bukkit forums and search:
Expminer
First of all there is a thing in this that detects when the ore has been placed and not naturally generated and you will not get xp from placed ores blocks.
It is also configurable how much xp you get per ore.
So ya i just figured i would throw this out there.