Vegetarian options are becoming more common in Egyptian restaurants, but the best bet remains ordering a variety of appetizers. Between stuffed vine leaves and hummus, yogurts and cheeses, and fresh bread, a good restaurant can provide a well-balanced and filling meal. Make sure you ask before ordering the stuffed vine leaves -- these are sometimes cooked with a small amount of meat inside.
One potential boon to vegetarian travelers is that the Christian community in Egypt maintains a rigorous fasting calendar. Unlike the Muslims, who abstain from food or drink during daylight hours, the Coptic community eschews meat and dairy products during their fasts. Enquire after "fasting foods" at restaurants and bakeries.
Happy Cow's Vegetarian Guide to Restaurants & Health Food Stores (www.happycow.net) has a restaurant guide with more than 6,000 restaurants in 100 countries, though at the time of writing, it has only one, outdated, listing for Cairo. Hopefully, this will expand with reader contributions. VegDining.com (www.vegdining.com) also lists vegetarian restaurants (with profiles) around the world. Vegetarian Vacations (www.vegetarian-vacations.com) offers vegetarian tours and itineraries.
