I could not wait any longer for a reply.  This looks like an unsupported, incomplete (not to mention buggy dev interface that crashes) product.  I purchased Dundas Guage, very powerful and robust.

using Infragistics.UltraGauge.Resources;

using Infragistics.Win.UltraWinGauge;

using System;

using System.Windows.Forms;

public class Form1 : Form

private UltraGauge ultraGauge1;

this.ultraGauge1.Dock = DockStyle.Fill;

LinearGauge lin = new LinearGauge();

linearScale.MajorTickmarks.StrokeElement.Color = Color.Black;

this.ultraGauge1.MouseMove += new MouseEventHandler(this.ultraGauge1_MouseMove);

this.ultraGauge1.MouseUp += new MouseEventHandler(this.ultraGauge1_MouseUp);

private LinearGaugeNeedle DraggingNeedle { get; set; }

this.DraggingNeedle.Value =

this.DraggingNeedle = null;

this.DraggingNeedle = null;

I too was looking for this. I was really hoping to see something along the lines of

needle.ValueChangedHandler += myValueChangedHandler(object sender, ValueChangedEventArgs e );

Any chance to see this in a future version?

 the UltraGauge control has a MarkerValueChanged event.

Does that mean that all the code posted by David Negley is not necessary? 

I will try this today.

Thanks

it is necessary if you want to make needles draggable on a linear gauge.

This is a unique need.