Fun with WPF4.5 and Rx

MainWindow.xaml.cs

using System;
using System.Collections.Generic;
using System.Reactive.Linq;
using System.Windows;
using System.Windows.Controls;

namespace waving_progressbars
{
    public partial class MainWindow
    {
        private const int NbBars = 80;
        readonly List<ProgressBar> _bars = new List<ProgressBar>();

        public MainWindow()
        {
            InitializeComponent();

            // Instanciante some ProgressBars
            for (var i = 0; i < NbBars; i++)
            {
                _bars.Add(new ProgressBar { Height = 10});
                Panel.Children.Add(_bars[i]);
            }

            Observable.Interval(TimeSpan.FromMilliseconds(40)).Subscribe(Wave);
        }

        public void Wave(long l)
        {
            for (int i = 0; i < NbBars; i++)
            {
                var t = Math.Cos((l + i*(100/15)) * (2D / (200D) * Math.PI));
                var tmp = i;
                Application.Current.Dispatcher.Invoke(() =>
                {
                        _bars[tmp].Value = 50 + t * 50;
                });
            }
        }
    }
}

/* View side
<Window x:Class="waving_progressbars.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" SizeToContent="Height" Width="525">
    <Grid>
        <StackPanel Name="Panel" Orientation="Vertical">
        </StackPanel>
    </Grid>
</Window>
*/