Move a character smoothly

How to move a character smoothly with analog stick of the Xbox 360 pad ?


The Xbox 360 analogs sticks deliver information of the range sticks are pushed:

GamePad.GetState(PlayerIndex.One).ThumbSticks.Left.Length() : float

If stick is idle 0, if stick is full throtle 1, mid-course 0.5 ...

I use this information as speed, and that's it.