Zachary Abel's "Poker Faces"
"Thirty standard playing cards are carefully slit and assembled into a configuration of six intersecting pentagonal prisms. Four of the prisms display royal flushes, the luckiest hands in poker."
Here's a PDF template that should print the card outline at the proper size. (Make sure scaling is 100% when printing.)
I cut all my cards at the same time using a scroll saw. I taped the 30 cards together into a packet and affixed the template on top before cutting through all the layers at once. Much easier than cutting each one by hand with scissors.
Learn all the details on how to make it at Zach's website.
Andrea Hawksley's "6 Card Ball"
A compact polyhedron of 6 interlocking cards. According to Andrea "a fun design where the interior figure is clearly a dodecahedron, but, since each card represents two faces of the dodecahedron, the symmetry group represented is pyritohedral."
Template and Assembly
Get the template and learn how to make it on Andrea's super cool website.