When you only have five or ten minutes, this is your Magic Variant. The game is played exactly the same, with some important differences.
1. At the end of each turn, a player may put any number of cards from his or her hand on top of his or library, and draw an equal number of cards.
2. Players may play any number of lands each turn.
3. During a players' upkeep, they may choose to skip their draw step, and instead draw until they have seven cards in hand.
Play this variant, with regular magic decks, not decks designed to abuse it, or else you will probably have 2 turn games!
In my own experience, I didn't like Speed Magic, but other people I know always play that way. Anyway, try it out, maybe you'll like it!