One of the stands at my local farmers' market sells some of my favorite olives and I always try to keep a container of them in my refrigerator.
The Eliki Olive Oil Company specializes gourmet olive oils, vinegars and other delicious foods imported from Greece. Their olive oil is organic and comes in interesting flavors such as Sun dried Tomato and Garlic, Rosemary, Chili Pepper, Orange Tarragon, and Lavender with Thyme. Their balsamic vinegar is sweetened with figs and comes in pretty, thick-glassed decorative bottles.
If you stop by the stand, it's more than likely that you'll be offered to sample some of their food products. They have all the standard Greek treats, from hummus and babaganoush to tazitki, fresh feta and plump baked giant beans. They also have nice soft pita to pull it all together.
You can find the Eliki Olive Oil stand at farmers' markets in West Hollywood, Torrance, Manhattan Beach, Culver City, Downtown LA, Westwood, and South Pasadena. However if you do not live in Southern California, you're in luck. The company has an extensive, informative website and they ship all over the world.