In John's account of the resurrection, he specifically notes that the napkin that covered Christ's face had been folded. This is an example of just how deep God's word goes. Aside from explicit, firm statements, there are little details woven within which, when you find them, really increase the wonder of it. So, what is the significance of Jesus folding the napkin? To understand this, it is important to understand Hebrew customs of His time.
We all know that Christ is our Master, and we are His servants. In Jesus' day, servants would arrange their masters' table in exactly the way he liked it, then leave the area, out of sight, but ready to either heed their masters' voice, or clean the table when he finished. When the master finished his food, he would stand up, clean himself off, then toss the napkin onto the table. This signified that he was finished, and the servant would clean the table.
But as we all know, sometimes, you have to get up before you've finished eating. When that happened, the master would fold his napkin and leave it next to his plate. This would signify to his servant that he was soon to return. From this, we see the significance of Jesus' folded napkin. He wasn't done yet: He is coming back!