Does anyone have any special, magical ways of reinforcing my 8-yr-old son's belief in Santa?

Don't put any of his gifts under the tree for x-mas. Take him out to the rest of the family on x-mas day and remind him that Santa do not visit none believing kids. Let him think about it for a couple of hours while you have someone at your house setting up things for his return. I promise you he will believe after thinking he had nothing coming!! Goodluck!!