Ting is grapefruit flavored soda that is very popular in the Caribbean. You can get it in the United States if you look hard enough (try an ethnic foods store or a Whole Foods).
If you are buying it in the United States, check the expiration date. Some of the product in the U.S. is really old.
In the Caribbean, Ting tastes something like Fresca and is quite refreshing. The Ting I've had in the United States tastes sweeter.