A simple one that I enjoy is to add red pesto (pesto princess makes different types of pesto, one is called 'red pesto' made with red peppers), and some fried chicken pieces.
Chop up some chicken breast into bite sized pieces (or smaller), and fry lightly (i genearlly add some pesto to that as well). Make the couscous, stir in some pesto, add the chicken and voila!
[best served hot/warm]
Another nice couscous salad is one they do at WW and checkers - drizzle some lemon juice over the couscous, and pieces of feta, some smallish cubes of cooked butternut, and some pumpkin seeds. yummy!
[yummy served cold]