This question comes up a lot. First, hydration IS important, but it seems there are lots of myths out there about water consumption (including, perhaps, the "clear pee" notion).
The newer research seems to indicate that we get hydration from many sources, even caffeinated beverages ADD fluids to your body. So as long as you get fluids of all kind (and there is liquid in many foods too) on a regular basis, you are probably fine and don't have to worry about drinking "enough." (though, do note the limitations in the conclusion of the article I indicated below).
Here's a link to a research article in the American Journal of Physiology that discusses the issue of whether there's any evidence we need to drink 64 ounces of pure water daily and some of the other issues too. Much of it is pretty accessible to the lay person, and quite interesting I think.
And here's the abstract:
"Despite the seemingly ubiquitous admonition to "drink at least eight 8-oz glasses of water a day" (with an accompanying reminder that beverages containing caffeine and alcohol do not count), rigorous proof for this counsel appears to be lacking. This review sought to find the origin of this advice (called "8 × 8" for short) and to examine the scientific evidence, if any, that might support it. The search included not only electronic modes but also a cursory examination of the older literature that is not covered in electronic databases and, most importantly and fruitfully, extensive consultation with several nutritionists who specialize in the field of thirst and drinking fluids. No scientific studies were found in support of 8 × 8. Rather, surveys of food and fluid intake on thousands of adults of both genders, analyses of which have been published in peer-reviewed journals, strongly suggest that such large amounts are not needed because the surveyed persons were presumably healthy and certainly not overtly ill. This conclusion is supported by published studies showing that caffeinated drinks (and, to a lesser extent, mild alcoholic beverages like beer in moderation) may indeed be counted toward the daily total, as well as by the large body of published experiments that attest to the precision and effectiveness of the osmoregulatory system for maintaining water balance. It is to be emphasized that the conclusion is limited to healthy adults in a temperate climate leading a largely sedentary existence, precisely the population and conditions that the "at least" in 8 × 8 refers to. Equally to be emphasized, lest the message of this review be misconstrued, is the fact (based on published evidence) that large intakes of fluid, equal to and greater than 8 × 8, are advisable for the treatment or prevention of some diseases and certainly are called for under special circumstances, such as vigorous work and exercise, especially in hot climates. Since it is difficult or impossible to prove a negativein this instance, the absence of scientific literature supporting the 8 × 8 recommendationthe author invites communications from readers who are aware of pertinent publications."