If a spell has a casting time of one swift action, does a scroll of that spell also take a swift action to activate, or does it still take a standard action?
Even if it's a scroll of a spell with a casting time of 1 swift action
A Scroll Takes a Standard Action to Use...
According to the Dungeon Master's Guide
Activating a spell completion item [like a scroll] is a standard action and provokes attacks of opportunity exactly as casting a spell does. (213)
...Unless One Uses the Rules Compendium
According to the Rules Compendium
Activating a scroll takes the same amount of time as the casting time of the spell stored on the scroll and provokes attacks of opportunity as spellcasting does. (85)
Talk to the DM. Battles rage over the rules in the Rules Compendium.