Are these brown finger-like things on the outside of my house caused by termites?
Those are definitely termite tubes. Those are the exploratory tubes that termites make when they come out of the soil and are exposed to air and light. They build the tubes out of dirt and their feces to protect them when out of the ground. Definitely termite tunnels. These are common on the side of a house, or inside a crawl space going up foundation walls.

DIY is definitely an option - a MUCH cheaper option. It's really simply in terms of knowing what to do, the hard part is the digging and drilling, but it's worth it when you know how much you will save. Read this article on my site to learn how to do it yourself: http://www.domyownpestcontrol.com/how-to-perform-termite-treatment-a-87.html