I add Kefir to a lot of dishes (both cooked and uncooked) that call for some dairy component. I actually prefer it to milk in things like pancakes, even though cooking it must kill some/many/all of the probiotics. I was making my own, but I was finding the process a bit more involved than I wanted to deal with, so I just recently started buying pre-made kefir.

I can't say that I've experienced a world-altering impact to my life (wow, no more acne and I've lost 22lbs!) but I do think I've been able to eat dairy products (cheese and yogurt) with far less upset stomach than before. Careful with introducing Kefir if you're looking to try it out - start small. I was adding a tablespoon to my dishes and it made me gassy as heck for the first couple of days.