On my last visit to Shang Hai, I noticed salted lemonade ($3) on the menu.
The server told me it is what it sounds like — with the salt enhancing the lemon flavor. (Basically, it's the same idea behind grandpa Gene salting the ice cream on Mad Men.)
And, indeed, it is very lemon-y, almost artificially so, and it reminded me of something I couldn't quite place. When I was paying up the server asked me what I thought about the drink, and I said it was okay. She noted that it reminded her of a margarita without the booze ... Bingo! That's exactly what it tastes like.