One of my biggest frustrations with Google Presentations has been the inability to easily align text and images.
With the addition of “snap to grid”, this problem is solved. You can now use the Alt, Ctrl, and Shift keys to fine tune object and text placement.
[ALT] while dragging turns off the grid and gives you smooth drag (use [OPTION] on a mac)
[SHIFT] while dragging enables vertical and horizontal dragging guides
[SHIFT] while moving an object with arrow keys enables 1 pixel nudge
[SHIFT] while resizing preserves the aspect ratio of the object
[CTRL] while moving leaves the original object and drops a duplicate in the new location