This is a discussion topic for the Ore project, OreGenUltimate. View the full project on Ore for downloads and more information.
OreGenUltimate is a plugin that generates ores from the mix of lava and water whereby the resulting product would usually be cobblestone.
The main use for this plugin would be on servers where there is no ability to mine ore in a feasible manner and miners can only get blocks by using a cobblestone generator. For Example a SkyBlock style map.