Sometimes engineers really are quite marvelous.

They think of things that no one else will think of, and those things turn out to actually be useful. Or, in very rare cases, amusing too.

Here is something that is both immensely utilitarian and entirely engaging.

NASA engineer Mark Rober used some red sauce and two iPad 2s in order to pretend, at whatever Halloween convention he might be attending, that he has a vast, open, and bloody wound through the core of his torso.

It is, as he says, simple. You tear a hole in your least favorite sweatshirt. You plant an iPad 2 in front and behind. You start a Face Time chat between the two. That's it.

Because he is a NASA engineer--and NASA engineers have to think of everything--he suggests that, should the Halloween party you go to be in a place with faltering Wi-Fi--don't forget to put a little hotspot in your pocket.

My stomach is agape with gratitude to Gizmodo, which seems to have first noticed this fine creation and even interviewed Rober about designing the next Mars Rover.

Some may feel it is expensive to get hold of two iPads. On the other hand, they are so ubiquitous that there will always be those prepared to give up theirs for the night, just to keep their friends happy. We all live to share these days, don't we?

I worry, though, that the penchant for copying so popular in some tech circles might mean that some San Francisco parties will see long-haired youths sulking because someone else is dressed just like them.