Long ago I learned the magic of simply placing a sprig of mint or lemon balm in my water bottle.  After a half hour or so the water takes on a lovely light taste of the herb.  My kids love herbal waters and I often put a sprig of mint into their water bottles if they are headed out and about for the day.  Yet when we spend the day at home, I have found that filling a pitcher with water and herbs doesn't seem to attract their attention.