Rulings

• The ability affects all players, not just you.2010-06-15
• The effect doesn't wear off until just before your next untap step (even if an effect will cause that untap step to be skipped).2010-06-15
• The types of mana are white, blue, black, red, green, and colorless.2010-06-15
• If a land produces more than one type of mana at a single time (as Boros Garrison does, for example), the land's controller chooses which one of those types of mana is produced by the delayed triggered ability.2010-06-15
• If a land is tapped for mana but doesn't produce any (for example, if you tap Gaea's Cradle for mana while you control no creatures), the delayed triggered ability won't trigger.2010-06-15