I've already posted a brief roundup of interesting models folded by Michal Kosmulski, expert orgami-ist and IT director at NetSprint. However, I didn't include my favorite model, because I felt it deserved its own post. Kosmulski folded an elaborate and large Sierpinski tetrahedron, which he deems "level 3" in difficulty. (Translation: hard). It is constructed with 128 modules and 126 links, based on Nick Robinson's trimodule.
Here's the only information given on its construction: "The links were made from narrow rectangular straps of paper by folding two flat pentagonal knots on each."
This would be an amazing future Math Craft project. The end result is really beautiful.