Kefir is wonderfully versatile. Here are some of the things I've used it for and I have included one recipe so far. I will post the others as time goes on:
Fresh kefir cheese (excellent used just like cream cheese)
Liquid kefir to drink straight and in smoothies
Liquid kefir as a culture for making raw milk hard cheese
Liquid kefir mixed half and half with fresh milk as a substitute for Buttermilk in baking
Kefir is a superior probiotic, and culturing your milk with kefir makes everything more "bioavailable"
I have used liquid kefir to make a sourdough starter for bread - very easy and very yummy bread
On Dom's Kefir site, he tells how to make a Yorkshire Curd Tart that is fantastic!