The pansy and johnny jump ups we grow ourselves and know they're organic are great for salads and other things - these aren't mine, but I have decorated cupcakes with them before. They are great in salads too :)
I use violets a good bit when they are in season, usually as a garnish as they are some trouble to pick for a main ingerdient, but i do use the leaves for most of the year. usually in salads or chopped in soups and omelets. The blue blossoms are esp nice added to the bowl in corn chowdwer, the flavor is great and the look is even better.
We had some Violet Cream chocolates for the first time in years over Christmas although they weren't quite the quality that allowed a little crystalised flower on the top. They do make such a showy topping for cakes though don't they!
I had both violet chocolates and rose chocolates when I was in the UK. Honestly - they tasted like chocolate-covered perfume. Ever get a little bit of perfume spray on your tongue? That's what they tasted like! I didn't like them at all.