Well, there are jacks all over the place, so this should be easy.
A jack-tar is a sailor, a jack-the-lad is an enterprising (though dodgy) person; every man jack is absolutely everybody. You can lift a car with a jack, or roast meat on one.
Jacks are in packs of cards and harpsichords:
illustration by Nojhan, English captions by Jeff Dahl
and games of, well, jacks, as well as games of bowls. You find them in electrical circuits (they're the female half of a connection that acts as a kind of circuit-breaker).
They fly from the bows of ships:
and another kind of jack forms part of a sailing ship's rigging.
They're to be found in tropical seas:
And in the USA jack is money, which gets everywhere.
In fact, now I come t think about it, we really won't be able to avoid Spotting this Frippet.
Nice easy day for us all, then.
Spot the Frippet: jack. This word is short for Jenkin, which is a pet form of the name John. This Hebrew name means blessed by God.