Cyborg brain removal

[Lantern]

You can click on an open-headed cyborg with an empty hand, change hands before selecting 'remove brain' from the menu, and pick up the brain into a full hand, with the usual consequences (anything you were holding disappears into the aether, its sprite and examine text remains). There's probably quite a few things you can do this with.

I think the same thing happens when building a flamethrower. Once you complete the last step, it's sprite disappears and the only way to make it reappear is to drop/throw it.