Appears that Kamal is right. If you take a "snapshot" (requires powering if off first) then "destroy" the image, even though the destroy button doesn't explicitly mention it (feature request: update the destroy button text to mention snapshots are not destroyed), the snapshot remains.
So next you go to "create droplet", select the same data center, then under "select images" you select the (oddly titled) My Images tab (suggestion/feature request: rename to "my snapshots" for consistency) then create it. It seems to reset the root password [huh wuh?] but besides that, you have the original box back. You can even create multiple clones of the original box whoa!