No I did not mean with weights in the hands, but there is a weight vest out there if you were really interested in it. You can also use a parachute, down hill running (very slight decline), there are bands that will kind of shoot you out like a sling shot, and there is also the towing tires. Those are all various sprinting training methods I can recall off the top of my head each of which train you to get better at various aspects of running.
You could also try other drills like agility drills (I just started incorporating these) the ones I'm doing are basic line drills where you jump in various patterns. But there is also the w drill which comes from football for training defensive backs. Great drill, you start off low, back peddle break down, sprint up break down, and do a w with it. You could also look up plyometric drills as well. Oh the hill is a great way to punish yourself! Try getting low and back peddling up the hill that really works the quads. Lunging, bear crawls, and other funny walking drills up the hill are also extremely difficult. There are so many different types of running drills you can do just pick a few that you enjoy or want to work at and do those.
Ohh also look up high intensity interval training (HIIT), it is sprint training as well also known as wind sprints. Very good form of training and much talked about here by vicious. It is easy to find using the search bar and is talked about how and when to incorporate that into your HST. From my personal experience it will get you allot faster just by doing that instead of any of the fancy stuff I mentioned earlier.