Here's a list of 10 (mostly) simple things to do with whey. I have not tried all of them, but just for the ideas. (For the record, the whey I have is acidic, which comes from making soft cheeses. Sweet whey is produced by hard cheese. I believe things like ricotta can only be made with sweet whey.)
1. A brown Scandinavian cheese (Brunost) commonly called Gjetost in the States is made entirely from whey! It's like a mixture between cheese and caramel apparently. Sounds good! (Here's a recipe. Just remember, you can't make it with your acidic paneer whey.)
Just ignore all the gluten surrounding it... Bad friends.
2. Replace water in any bread recipe with whey. (I saw one suggestion to proof yeast with warm whey and honey and then add to flour for flatbread.) Whey is said to give breads a softer texture. It's especially helpful in slowrise breads like sourdough because of the bacteria it contains.
3. Also because of this bacteria, whey is great for pickled things like onions, sauerkraut, and regular ol' dill pickles.
4. You can replace buttermilk with whey in essentially any recipe (take ranch dressing, for instance).
5. Once again thanks to its healthy bacteria, whey can be added to the soaking water of legumes or grains, which improves digestibility.
6. Season with garlic and/or onions and use it to cook rice or polenta.
7. Whey makes a good marinating liquid! The enzymes in the whey help carry flavors deep into the meaty tissues, improving both texture and taste. It's especially good for meat that has been frozen.
8. Whey can be used in place of or in addition to soup stock.
9. Adding whey to smoothie drinks gives a healthy boost in protein.
10. Poured into bath water, whey can give skin nourishment, too.
There you go! I think? this stuff is supposed to be good for your gut chemistry thanks to the bacteria (have I mentioned that enough?), similar to kefir. Don't quote me on that one, though.
Also worth noting is the fact that whey keeps for quite some time in the fridge (try 6 months?!) and freezes well to boot. Freeze in an ice cube tray, then transfer the cubes to a Ziploc bag and back into the freezer.
Oh yeah! Animals like whey as well! Especially cows, I hear. And cats and dogs. And chickens. And pigs? Maybe I should give some to my cat. She's looking pretty... shabby these days. I'd add this to the list but 10 is such a nice little number...