While running away from something, let's say a tank, you sometimes need that last extra speed boost. So I suggest a dive move. The character launches himself forward, moving faster than jumping, running, sprinting, but losing a lot of stamina in the process, and ending up prone (or if one still has stamina left, can stand up and move further). Since this is such a stamina-draining move, it would not be abused all the time. Also it should screw up aiming with weapons, so you can't pull off any TheSpecialists-like stunts. How can this be useful? Diving out of the way of a vehicle, since you get a helluva speed boost. Diving out of the way of a grenade. Diving out of enemy fire. Just plain diving to get a little bit closer, end up prone, and be able to set up your HMG.
That would be so epic cool. Maybe loose 5-10hp depending on the material you are diving into. Metal 10hp damage, water 0.
Reminds me a bit of 'panic mode' from Zombie Panic where you drop all your weapons and ammo and run real fast for a while to flee the horde of zombies chasing you. I don't know if a dive function would be necessary though, it's already quite easy to run from nades and dodge tanks (at least if there's cover somewhat close).
Sounds cool, although someone would have to animate it...leading to it never being done. So...nice suggestion, but you'll never see it.
So you want the dodge system from unreal tournament. I can't say I can imagine it being useful, but as I don't have to use it I don't mind.
Ok, the dodge system from unreal tournament except you go prone at the end. You'd probably have to use the UT controls because all the other buttons are in use.