I love the idea of food trucks, but there's not a lot around where I am.  Do you have any good food trucks near you?
This is such a cool topic as a friend recently bought a truck to cook and sell food in. His is the first I have seen in our area.
Nice!  Before I moved there was one I liked near my office, it did a weird asian fusion thing.  What kind of food does your friend serve?
For right now it is mostly just hamburgers, fries, and sandwiches. But he is a culinary artist and plans to expand his menu quickly to a much larger variety.
That's good.  Nothing wrong with basic good food, but it's always a good idea to go with something that makes you stand out.
The only other food truck I remember in our area is called Dem Brothers and a Grill. They started out similar to my friends but have now bought their own restaurant focusing more on ribs and other street foods.
That's the goal of any food truck I think.  Is your friend hoping to open a stationary restaurant at some point?
No, he actually likes being able to be portable and travel to different areas. 
That's valid.  I bet he can pretty easily adjust to market trends by just up and moving to a new place.
I had no idea food trucks were so popular but apparently in the US they serve more than 2.5 billion people every day