An additional note:
1) Vertical aim doesn't matter at all. The only aiming that matters is left/right horizontal.
2) Video was made with a STRAFEBOT to show the ideal mouse movement for strafejumping.
3) The jumping is done just to avoid ground friction, you could still accelerate the same way on a frictionless surface without jumping.
4) The keypresses/strafehelper/speedometer are part of a clientside mod which can be downloaded here http://www.playja.pro . Install it to the gamedata/base or gamedata/japro or gamedata/japlus folder (or whatever server mod you want it to be active on).
5) The map used is racearena_pro

Rendered via jaMME, Sony Vegas 12

Music: Nujabes - Light on the Land