My soda consumption (along with my waistline) has gone down drastically since keetara pointed me in the direction of the Crystal Light shakers. They have all kinds of flavors, and only 5 calories per 16-oz serving (though, personally, I use 24 oz bottles). If you don't like Nutrasweet, the 4C brand of shakers uses Splenda.

I'm with you on the diet drinks, though. The only ones I can tolerate are Diet Dr Pepper and Coke Zero - so when I have to have soda, it'll be one of those.