Suitable oil for woking?
You want to use an oil that will handle the hotter temperatures of a wok. This list of oil smoke points suggests that most refined oils will work fine. Don't use unrefined oils or butter because they'll burn. 

Once you've got an oil that will handle the heat, you want something that will taste good. I think that's the main issue with olive oil. There aren't olives in asian cuisine and I think that would taste a bit funny. I tend to use vegetable or canola oil for the majority of my stir-frying and then add a little sesame oil towards the end (generally when sauteing garlic and ginger). The sesame oil adds a strong asian flavor to the food. I've tried just using sesame oil, as a recipe sometimes recomends, but I find the flavor overpowering. Unrefined sesame oil is fairly common at the grocery store, and you don't want to use that as it will burn in the wok (but it could be drizzled on the food after cooking).