I have an SE Focus with the Sports Package. When driving almost exclusively on city streets, I get 29-30 miles.
If I go exclusively on the highway (doesn't happen often, but I've done it often enough), the car gets 39 - 40 MPG! (I live in Florida and it is very flat...I think that contributes to the high MPG).
Most of the time however, I do approx 70% city and 30% Highway and I am averaging about 31-32 MPG.