Dynamic shadows in Unity pro using an orthogonal camera. Use as shader for all objects that need to cast and/or receive shadows.

ArxOrthoShadows.shader

Shader "ArxOrthoShadows" {
Properties {
	 _Color ("Main Color", Color) = (1,1,1,1)
	 _MainTex ("Base (RGB) Gloss (A)", 2D) = "white" {}
	 _BumpMap ("Normalmap", 2D) = "bump" {}
	 _Detail ("Detail (RGB)", 2D) = "gray" {}
}
SubShader {
	Tags { "RenderType"="Opaque" }
	LOD 400

	CGPROGRAM
	#pragma surface surf BlinnPhong fullforwardshadows
	sampler2D _MainTex;
	sampler2D _BumpMap;
	sampler2D _Detail;
	fixed4 _Color;

	struct Input {
		float2 uv_MainTex; 
		float2 uv_BumpMap;
		float2 uv_Detail;
	};

	void surf (Input IN, inout SurfaceOutput o) {
		fixed4 tex = tex2D(_MainTex, IN.uv_MainTex);
		tex.rgb *= tex2D(_Detail,IN.uv_Detail).rgb*2;
		o.Albedo = tex.rgb * _Color.rgb;
		o.Gloss = tex.a;
		o.Alpha = tex.a * _Color.a;
		o.Normal = UnpackNormal(tex2D(_BumpMap, IN.uv_BumpMap));
	}
	ENDCG
}
Fallback "VertexLit"
}