Microsoft’s PowerPoint Team blog outlines some of the lesser known key-and-drag combinations for moving items around on your slide. Holding down alt while dragging temporarily switches PowerPoint’s automatic alignment grid off (useful for precise placement). Ctrl+drag copies an object, and Shift+drag lets you move in a straight line horizontally or vertically. That might not be new information if you’re a PowerPoint veteran, but for occasional dabblers, it’s good stuff.
Key information [Powerpoint Team Blog]