variable precision gui slider control

I'm looking for information of a ui slider control whose step size is influenced by the distance between the ui control and the users mouse pointer.

For example:

You have a slider control which slides horizontally. It has a value range of 0 to 1000. It occupies about 100 pixels on the screen. So, when you slide the control using the mouse, the smallest step size/increment available would be about 10. The idea is, you could mousedown on the control as you normally would, but if a smaller step size is desired, you simply move your mouse away from the control, vertically, and the step size would decrease more and more as the mouse gets farther and farther away. This way, you could slide your way to a value such as 453.2 if desired.

I feel like this is something that probably already exists. I just can't find any existing implementations, and I'd like to see what others have done before I set out writing my own. Does someone know of a name, a demo, or a discussion for something like this?

Edit-

Examples or demos from any language/platform is fine. I'm more interested in seeing what/how/why others have done it however they did, although I'll be implementing it in java开发者_如何学JAVAscript.

So I asked this question almost 5 years ago...today I finally found a great real world example! I noticed in youtube if you're viewing a long video, they implement my idea. Here's a youtube video which demonstrates it, just hold your mouse down on the slider button and move your mouse up a bit to see it. I think this slider is awesome, if I may toot my own horn lol.