Bob's reply above is exactly what my high school cross country coach had us do for our "speed work" during the week. Once the season started, we'd have two practice days and the balance of the week would either be meets or prep for meets, or recovery after. It's good stuff and it'll teach you the mental toughness, if you push yourself.

You can also do a little speed work while you're doing your long distance runs. Make a bet with yourself - Bet you can't sprint three telephone poles down the road, or to that stop sign or whatever. Then do it, but don't let yourself walk afterwards- slow to a jog and keep on going, gradually recover back to your regular pace. It can keep the running more "interesting". Additionally, you'll teach your mind that you can recover while running.

As far as land nav- a fellow lieutenant and I went to an orienteering meet once. It wasn't great as far as compass/pace kind of land nav, but it certainly gave us some better experience at terrain association. If you're hungry for something to do to improve your land nav and there's any kind of orienteering group near where you are, it certainly couldn't hurt.