double-side shader refer to http://forum.unity3d.com/threads/two-sided-cutout-shader-for-u3-wanted.93189/

AlphaTest-DiffuseBack

Shader "Transparent/Cutout/DiffuseBack" {
Properties {
	_Color ("Main Color", Color) = (1,1,1,1)
	_MainTex ("Base (RGB) Trans (A)", 2D) = "white" {}
	_Cutoff ("Alpha cutoff", Range(0,1)) = 0.5
}

SubShader {
	Tags {"Queue"="AlphaTest" "IgnoreProjector"="True" "RenderType"="TransparentCutout"}
	Cull front
	LOD 200
	
CGPROGRAM
#pragma surface surf Lambert vertex:vert alphatest:_Cutoff 

void vert (inout appdata_full v) {
          v.normal = -v.normal;
      }

sampler2D _MainTex;
fixed4 _Color;

struct Input {
	float2 uv_MainTex;
};

void surf (Input IN, inout SurfaceOutput o) {
	fixed4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color;
	o.Albedo = c.rgb;
	o.Alpha = c.a;
}
ENDCG
}

Fallback "Transparent/Cutout/VertexLit"
}

AlphaTest-DiffuseDoublesided

Shader "Transparent/Cutout/Diffuse Double sided" {
Properties {
	_Color ("Main Color", Color) = (1,1,1,1)
	_MainTex ("Base (RGB) Trans (A)", 2D) = "white" {}
	_Cutoff ("Alpha cutoff", Range(0,1)) = 0.5
}

SubShader {
	UsePass "Transparent/Cutout/DiffuseBack/FORWARD"
  UsePass "Transparent/Cutout/Diffuse/FORWARD"
}

Fallback "Transparent/Cutout/VertexLit"
}