Control the led blinking frequency with a potentiometer :
using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.NetduinoPlus;

namespace NetduinoPlusApplication1
{
    public class Program
    {
        public static void Main()
        {
            OutputPort blu_led = new OutputPort(Pins.GPIO_PIN_D0, false);
            //AnalogInput pot = new Microsoft.SPOT.Hardware.AnalogInput(SecretLabs.NETMF.Hardware.NetduinoPlus.AnalogChannels.ANALOG_PIN_A0);
            AnalogInput pot = new AnalogInput(AnalogChannels.ANALOG_PIN_A0);
            int pot_value = 0;

            while (true)
            {
                pot_value = (int) (pot.Read() * 255);
                Debug.Print(pot_value.ToString());
                Debug.Print(pot.Read().ToString());

                blu_led.Write(false);
                Thread.Sleep(pot_value);

                blu_led.Write(true);
                Thread.Sleep(pot_value);
            }
        }

    }
}