actually the last person who posted is only mostly right.. Technically it would be possible to turn lead into gold, but the sheer amount of energy needed for the reaction does not make this a financially viable option. It would cost far more to produce the energy required than the small amount of gold is worth.
The closest thing to a philosophers stone you'll ever see, is a fusion reactor. Invent that, and you have your philosophers stone. It's just very different than they had thought it would be.
That being said, you're not becoming immortal ever, no matter how much energy you can make, it's not happening.