I love small local cafes. Will I have any luck finding one in Arlington?

Definitely. Even just around Vassar College there are a couple. One is called the Cubby Hole and another is The Crafted Kup, both of which fit the description of small local cafes. You don't have to be a Vassar student to go to either one, and I happen to know the general population frequents them as well. There's another place at the big traffic circle called Juliet Cafe, but it's not a small coffee shop -- it's more of a restaurant, but admittedly the only times I've ever been there were to play pool.