You'll need:
White chocolate morsels
Oreos (I don't need to tell you that I use Double Stuf, that should be a given)
Crisco
Sprinkles (optional)
Melt your white chocolate in a double boiler.

I don't have a double boiler so I took a cue from Kim and used a glass bowl with my regular saucepan. You can also melt the chips in the microwave, but I think it's easier to scorch them that way, and once that happens your chocolate is ruined.
I mentioned in an earlier post that I'm not a huge fan of white chocolate. That's true for the most part, except when it comes to these Oreos.
Also, I found (from reading the back of the morsels bag) that if you add a tablespoon of vegetable shortening (I love the Crisco sticks) to your chocolate, it helps make it a bit thinner and therefore better for dipping.
Once your chocolate is just melted (be sure not to cook it too long!) remove the bowl from the water/heat and throw in your Oreos.

Get them nice and covered, and then fish them out with a fork and shake off the excess.

I transferred them to my Silpat, but you could also use wax paper.

Hit them with a shot of sprinkles and voila!

If you have leftover chocolate, you can cover all sorts of other stuff: pretzels, graham crackers, my mom used to even make little Ritz cracker and peanut butter sandwiches and cover those. Yum!