I personally gave up counting water intake. There is no real health basis for drinking 8 X 8 oz glasses a day, it was just a standard someone thought up in the 1950's. Drinking too much water can cause problems with vitamin absorption and throw your electrolytes out of whack.
That said, people definately should drink when thirsty and aim to drink through out the day to help stay hydrated and curb appetite.
From what I've read, any liquids count towards fluid intake...even vegetables with a high water content. But you need to drink more pure water if you are drinking something that is a diuretic like coffee in order to really hydrate yourself.
I personally do count tea towards my water intake and I would think Crystal Lite would count too. As it is pretty much chemicals though, it would be healthier to eventually switch to adding lemon or lime....I don't think you'd want to drink that all day for the rest of your life, but it's probably fine in the short term for getting used to drinking extra liquids.
Here is a great article on why you don't really need drink if not thirsty.
http://www.scientificamerican.com/ar...-water-per-day