The thin crust pizza from pizza hut is vegan although I've never had it (the other crusts aren't vegan as far as I know).
Chipotle is great - black beans, grilled veggies, salsas. I'm not sure if their rice is vegan, I think it is but I never get the rice. The tortillas may be vegan as well again I don't know because I don't get the tortillas.
Vegan restaurants - I would suggest searching some out
Chinese restaurants - it varies from place to place but chinese food generally doesn't use dairy and you can ask for no egg.
Thai restaurants - they do use fish sauce but many places will omit if you ask.
Other restaurants - honestly, just ask. You can generally navigate the no dairy, no egg, no meat in most restaurants. Some places use meat broth so you do have to be careful of that. Some veggie burgers aren't vegan and often times bread isn't always vegan. It really does depend on your comfort level. If you want to be 100% vegan, sometimes it can be difficult in an omnivore world if you rely on others to cook your food for you.
Here are some other sites to reference:
http://www.vegcooking.com/restaurantGuide.asp
http://www.vegcooking.com/ChainRestaurants.asp
http://www.happycow.net/
http://www.vrg.org/restaurant/index.htm
Also, depending where you live, you may be able to find an online veg guide for your area. DC has vegdc.org which is great for identifying veggie options at restaurants in the area.