It's been hurting since late this morning. I'm assuming it's the (lack of) caffeine. I picked up a bottle of something organic called "Honest Tea" at Whole Foods. It says it has half the caffeine of coffee, which isn't much. The taste isn't much, either. I like the Passion tea I got at Starbucks yesterday during my bike ride a lot better.
Anyone got a no/low-cal beverage with caffeine they love that ain't carbonated or coffee-flavored?