Well, yogurt cheese actually.
500g Greek yogurt
1 level tsp salt
Mix the yogurt and the salt together. Put it in a sieve, lined with cheesecloth or muslin, over a bowl. Cover it with another cloth (or clingfilm) and put it in the fridge for a day or so. Throw away the whey that has collected in the bottom of the bowl, and turn the cheese out of the cheesecloth into a plastic container. This really fresh-tasting cream cheese should be eaten it within two days. You can mix in chopped chives or other herbs, black pepper, or even a little garlic.
Update February 2016: I got a yogurt cheese strainer for my birthday, and having used it quite extensively since then, I’ve discovered that you don’t actually need to put in the salt for this to work. Good news if you’re trying to restrict your salt intake.