Heres the full script:

var myLeft:float = 0;
var myTop:float = 0;
var myWidth:float = 200;
var myHeight:float = 50;

var isDragging:boolean = false;

function OnGUI()
{
    if (     GUI.RepeatButton( Rect(myLeft, myTop, myWidth, myHeight)  , "Moving Button" )   )
        isDragging = true;

    if (isDragging)
    {
        myLeft = Input.mousePosition.x - myWidth*0.5;
        myTop = Screen.height - (Input.mousePosition.y + myHeight*0.5);
    }
}

function Update(){

    if (    Input.GetMouseButtonUp(0)   )
        isDragging = false;

}

Just replace the words in the button with a texture of your object so it looks like you're dragging stuff.

var myLeft:float = 0;
var myTop:float = 0;
var myWidth:float = 200;
var myHeight:float = 50;

var isDragging:boolean = false;

// Add this line
var myInventoryImg:Texture2D;

function OnGUI()
{
    // if (     GUI.RepeatButton( Rect(myLeft, myTop, myWidth, myHeight)  , "Moving Button" )   )

      // Replace with this
      if (     GUI.RepeatButton( Rect(myLeft, myTop, myWidth, myHeight)  , myInventoryImg )   )
        isDragging = true;

    if (isDragging)
    {
        myLeft = Input.mousePosition.x - myWidth*0.5;
        myTop = Screen.height - (Input.mousePosition.y + myHeight*0.5);
    }
}

function Update(){

    if (    Input.GetMouseButtonUp(0)   )
        isDragging = false;

}

Thx for denewbie...it really works :)

BTW 4 oliver jones if you haven't get it done ( I guess you'd already figure it ou), maybe you'll want to use custom skin to change the button images :)