GoLightly has come out with an assortment of sugar free toffees, from chocolate, vanilla, coffee and peanut. These are 0g net carbs per serving.
Note that even at 0g net carbs, these have a whopping 34g of sugar alcohols per 7 pieces. You should really try just a few of these to see how your intestines react to them before you go whole hog on them.
The main comment on these is they are VERY sticky on your teeth. If you bite into one of these, don't expect it to loosen from your tooth for quite a while. Anyone with dental work will want to be VERY cautious with these. You almost want to just suck on them for a while before you start letting them near your teeth.
The flavors are good but a bit off. The coffee tastes almost raisiny. The vanilla is sort of plasticy tasting. Still, I don't imagine most people eat toffees for the brilliant flavors. They just want to gnaw on someting.
I enjoyed that the packaging has 'sugar free' in all sorts of languages! Senza zucchero - sans sucre - sin azucar - zucker frei - sugar free plus what appears to be Arabic and Hebrew. You learn something while you gnaw :)
A good candy to have to feed to the perpetual talker in your group of friends. This should keep him or her quiet!
Lisa Shea's Library of Low Carb Books