ConvertIEnumerableToDataTable.cs

// LINQPad Example
// Updated from http://davefancher.com/2010/04/16/linq-ienumerable-to-datatable/
// Defines an extension method that creates a new System.Data.DataTable from an IEnumerable<T>
// Even works with anonymous types

public static class IEnumerableExtensions
{
    public static DataTable ConvertToDataTable<TSource>(this IEnumerable<TSource> source)
    {
        var props = typeof(TSource).GetProperties();

        var dt = new DataTable();

        foreach (var p in props)
        {
            dt.Columns.Add(p.Name, p.PropertyType);
        }

        foreach (var r in source)
        {
            dt.Rows.Add(props.Select(p => p.GetValue(r, null)).ToArray());
        }

        return dt;
    }
}

void Main()
{
    new[] {
        new { ID = 1, Name = "Dave", DOB = DateTime.Parse("1978-08-02"), Amount = 1.23d, Flag = true },
        new { ID = 2, Name = "Fancher", DOB = DateTime.Parse("2001-02-03"), Amount = 2.34d, Flag = false }
    }.ConvertToDataTable()
    .Dump();
}