Stevia is a great alternative. Don't use the packets, though, or you get the same carbs as in Splenda... it's the maltodextrin, or whatever filler they use to bulk it up so you can see it when you're using it, that adds carbs.
If you're going to try Stevia, I recommend the NOW brand... it seems to be less bitter than others. And whatever you do, don't buy the commercial liquids... they're terribly bitter. Buy the powder. You can make your own liquid to use, the same strength as liquid Splenda (for those of us who can't find liquid Splenda! Great alternative in baking, etc.).
Here's how to make the liquid (using the NOW brand powder). This is 600 times sweeter than sugar:
1 oz. NOW brand powdered stevia concentrate, dissolved in 2/3 cup water
If you can't find NOW brand, I've also made the same strength this way: .9 oz. SweetLeaf brand powdered Stevia concentrate, dissolved in 3 1/8 oz. of water
Here's the sweetness equivalents:
1 t. extract powder = 4.16 cups sugar (200/48) = 1t. liquid
1/2t. powder = 2 cups sugar (96 teaspoons) = 1/2t. liquid
1/4t. powder = 1 cup sugar (48 teaspoons) = 1/4t. liquid
1/8t. powder = 1/2 cup sugar (24 teaspoons) = 1/8t. liquid
1/16t. powder = 1/4 cup sugar (12 teaspoons) = 1/16t. liquid
1/32t. powder = 1/8 cup sugar (6 teaspoons) - 1/32t. liquid
Another note about stevia... it's been known to have a bitter taste... that comes from using too much. It's soooo sweet, that once you add too much, it over powers your sweet taste buds, and becomes bitter. As the sweetness dissapates, you're left with a sweet aftertaste. Start with a little, and add if necessary. You can also blend a little stevia with another sweetner (Splenda, sucralose syrups like DaVinci, sugar alcohols like xylitol or erythritol, or Diabetisweet, to help with the sweetness/bitterness problem.