You can get the "liquid splenda" atlowcarber.com. It's not exactly liquid splenda since it's not as concentrated, but it is VERY sweet. It's a little pricey at first glance($17.99 US+ shipping), but since you only use a few drops per cup of coffee or tea, it's really a good deal. In the long run it's cheaper than packets of splenda.
From site:
8oz bottle equals the sweetness of 32 cups of sugar
4 drops = 1 tsp of sugar sweetness
1.5 tsp = 1 cup of sugar sweetness

That is a saving of over 768 carbs over the equivelant amount of powdered artificial sweetener. And on average a savings of $40.85 over 50 ct or 2 cup bulk boxes of powdered sweeteners.

I just got mine the other day in the mail and have made mock danish and peanut butter cups with it. Tasted really good in both and saved me carbs. The shipping time was a little long, about 2 1/2 weeks, but to me it was worth it.