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Same I love sprints and I believe it strengthens the ankles in a way that can transfer to jumps (at top speed sprinting that is).

Acceleration:
<a href="http://www.youtube.com/watch?v=SebLUQFWFz0" target="_blank">http://www.youtube.com/watch?v=SebLUQFWFz0</a>


1. Work on keeping your heels low, as opposed to cycling the heels as they do near higher velocities and top speed. Takes some strength but kick the feet out for the first 6-7 steps. Maurice did it well in this video. In other videos of asfa you can clearly see his start is utilizing this technique.The theory is that minimzing the distance the foot travels, by keeping the motion as horizontal as possible for the first several steps, will result in faster block start.
Asafa:
<a href="http://www.youtube.com/watch?v=y_vPi01jpBY" target="_blank">http://www.youtube.com/watch?v=y_vPi01jpBY</a>

You can see what I mean by heels low and kicking legs out more.



Top speed:

<a href="http://www.youtube.com/watch?v=YaM3wF6MRto" target="_blank">http://www.youtube.com/watch?v=YaM3wF6MRto</a>

1. Watch the slow mo. It's mostly a strength/activation thing to be able to run like bolt. If you squat too often, and end up being quad dominant, you won't extend the knee like that.

2.
<a href="http://www.youtube.com/watch?v=tiLeM6STHXI" target="_blank">http://www.youtube.com/watch?v=tiLeM6STHXI</a>
THis is HPC sport's video, it's nice but it's too based in science and HPC isn't producing the sprinters under 10 or anything. They emphasize step over drive down. I've done this before but I generate too much vertical impulse and I run faster looking down sometimes and kicking the foot out rather than knee up.

THis video also talks boaut generating higher vertical velocities, probably based on studies that vertical velocities are important for top speed sprinting, but that is hotly debated.

Edit: I fixed the embedding

Your best bet is to get a sprint coach who knows what he is talking about.  If that's not possible you should at least get yourself on video and upload to this site or another more sprint oriented site and see if you can get some advice. 

I would advise against trying to copy runner's like Asafa Powell.  Asafa has INCREDIBLY strong strength to weight ratios and his hipflexor development is outrageous.  He is able to start with his lead leg only about 1 foot behind the line.  People have analysed every part of his technique from his low heel recovery and his toe drag on the start.  He is incredibly fast, but I really would recommend against actively trying to drag your toe or replicate his low heel recovery.  Many sub-10 sprinters have much higher heel recovery.  You really have to do what works for you.  Honestly, in coaching sprinters I try not to do too much critique when it comes to form, unless it is really egregious.  There are some obvious examples of poor sprint form that can be fixed (arms coming across the midline, tilting the body back as one attempts to reach max V, etc), but beyond those most form issues are fixed by making the athlete stronger or looser.  Until you can get a video up or get a sprints coach I would follow these rules:

1) Make sure you are not carrying any bodyfat
2) Make sure you incorporate work at Max or near Max velocity (flying 60s, etc), as well as tempo work.
3) Get strong in the gym and strong at your drills.
4) Don't neglect your hip mobility work or any of your dynamic stretching. 

As you get stronger on the track and get faster your form will improve. As Charlie Francis used to say:  "If it looks right, it flys right!"
 

Could be weak glutes, cause be fatigue  could be a lot of things.  Often happens when people try to accelerate after they are already at top speed.  It's important to relax and remain neutral after you hit top speed.  A lot of tempo work should fix this.