This is a modified version of another Lab Maniac deck I found on Google (http://forums.mtgsalvation.com/showthread.php?t=485964), with some modifications to improve looting and protect against aggro decks' early attacks.
This is obviously a casual deck, but one that can hold its own against some fairly competitive decktypes in Standard. With life gain running rampant in Standard, it pays to think creatively to find an alternate win con. Why not one that draws your entire deck in the process?
The idea is to use looting spells (Faithless Looting, Alchemy, both Charms) to search out Enter the Infinite and throw it into the graveyard. Once there, you need to draw (and keep!) Spelltwine to copy Enter the Infinite from your graveyard. Ideally, that happens turn five or six--and fairly consistently, I might add. On the next turn, you draw your final card, play Laboratory Maniac, and cast Faithless Looting to win. If they try and remove Maniac, cast Izzet or Dimir Charm in response.
For a combo deck, this seems to pull things off with a surprisingly high accuracy rate. With the insane number of draw spells in here (21, including Augur of Bolas), it's not too difficult to find Spelltwine, and draw-ditch Enter the Infinite. My first tournament with the deck, it found the two combo cards in seven out of ten games. It won two matches, and two of my game losses happened the turn after I played Spelltwine...sometimes you just don't draw it in time.
Besides its surprising consistency, this Johnny deck is also a hell of a lot of fun to play. Who doesn't want to draw their ENTIRE deck as part of a win condition? If you've never won with a Lab Maniac in Standard, it's worth trying just to see the look on your opponent's face after you draw your deck, play him, and draw one more time. That said, this deck definitely has its weak points:
1. Aggro Decks. Fast-paced decks put this on a very short clock, and the answers are tied up in your Charms, which you'll also need to loot and draw in many cases. Rolling Temblor helps against Goblins and other weenie decks, while Augur of Bolas and Rakdos Keyrune provide some stable blockers, but this isn't too reliable. Your best bet is a heavy sideboard strategy, pulling in Searing Spears to help even out creatures or push your Rakdos Keyrunes into lethal territory.
2. Creature-Based Decks. The current standard environment plays a lot of badass creatures, and in some cases, almost no Sorceries or Instants. Decks like The Aristocrats (http://magic.tcgplayer.com/db/deck.asp?deck_id=1097795) leave almost no targets for Spelltwine, making the combo DOA. I'm not sure what to do about this, other than work out a more transitional sideboard.
3. Graveyard Hate. There are much better decks in Standard right now that rely on the graveyard to play their best spells, which unfortunately means that players are packing Rest in Peace and the like in the sideboard. This can obviously ruin this combo in no time. Odd-but-awesome: Grafdigger's Cage does nothing against this combo, since Spelltwine copies the spell, not the card, and plays them from exile.