I'd say Agersea has it right. I found a picture of them and they are exactly the same In shape.
I don't know if the pic will load (first time trying to load a pic) so here is the link:
http://www.artsandcraftskorea.com/acecart/bin/shop.cgi?action=view&itemID=ACHAT019&cate=040500000
The quote below also states that the 2002 World cup was held in Korea. Id say they are commemorative Korean jacks from that event. Mystery solved!!
"The 2002 FIFA World Cup, the 17th staging of the World Cup, was held in South Korea and Japan from May 31 to June 30. The two countries were chosen as hosts by FIFA in May 1996. For the first time in its history, the World Cup was organized by two countries. It was also the first World Cup held in Asia, and the first held outside Europe or the Americas. Brazil won the tournament for a record fifth time, beating Germany 2-0 in the final."
Hallelujah
Troy