Thank you kindly, MPallari, for a patch that:

This patch adds new property to ScenePresence: SpeedModifier. 
With this, one can modify avatars speed from region module 
or MRM script.

1 files changed, 9 insertions, 1 deletions

diff --git a/OpenSim/Region/Framework/Scenes/ScenePresence.cs b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
index 0eefd06..7300a24 100644
--- a/OpenSim/Region/Framework/Scenes/ScenePresence.cs
+++ b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
@@ -122,6 +122,8 @@ namespace OpenSim.Region.Framework.Scenes
         private bool m_useFlySlow = false;
         private bool m_usePreJump = false;
 
+        private float m_speedModifier = 1.0f;
+
         private Quaternion m_bodyRot= Quaternion.Identity;
 
         public bool IsRestrictedToRegion;
@@ -563,6 +565,12 @@ namespace OpenSim.Region.Framework.Scenes
             set { m_inTransit = value; }
         }
 
+        public float SpeedModifier
+        {
+            get { return m_speedModifier; }
+            set { m_speedModifier = value; }
+        }
+
         #endregion
 
         #region Constructor(s)
@@ -2224,7 +2232,7 @@ namespace OpenSim.Region.Framework.Scenes
             Vector3 direc = vec * rotation;
             direc.Normalize();
 
-            direc *= 0.03f * 128f;
+            direc *= 0.03f * 128f * m_speedModifier;
             if (m_physicsActor.Flying)
             {
                 direc *= 4;