C#

public class ContactViewModel : ViewModelBase
    {
        public ObservableCollection<Contact> ContactList;

        public ContactViewModel()
        {
            ContactList = new ObservableCollection<Contact>(cbdc.Contacts);
        }

public class ConversationViewModel : ViewModelBase
    {
        public ObservableCollection<Conversation> ConversationList;

        public ConversationViewModel()
        {
            ConversationList = new ObservableCollection<Conversation>(cbdc.Conversations);
        }

    }

public class ViewModelBase: INotifyPropertyChanged
    {
        public ContactLinqToSQLClassesDataContext cbdc = new ContactLinqToSQLClassesDataContext();


        #region INotifyPropertyChanged

        public event PropertyChangedEventHandler PropertyChanged;
        internal void RaisePropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }
        #endregion

<ListBox x:Name="ContactsLstBx" HorizontalAlignment="Left" Height="289" Margin="10,50,0,0" VerticalAlignment="Top" Width="115" ItemsSource="{Binding ContactList}">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding Path=Name}" />
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
        <ListBox x:Name="ConversationLstBx" HorizontalAlignment="Left" Height="134" Margin="333,50,0,0" VerticalAlignment="Top" Width="115" ItemsSource="{Binding ConversationList}">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding Path=Title}" />
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>