Refactoring of code in Scott Hanselman's post: http://www.hanselman.com/blog/TheWeeklySourceCode53GeterDoneEditionXMLInTheLeftHandBecomesHTTPPOSTsInTheRightHand.aspx

gistfile1.cs

using System;
using System.Linq;
using System.IO;
using System.Xml.Linq;
using System.Threading;

namespace TumblrAPI.ConsoleApp
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Started...");

            TumblrAPI.Authentication.Email = "myemail@notyours.com"; //Console.ReadLine();
            TumblrAPI.Authentication.Password = "poopypants"; //Console.ReadLine();
            if(TumblrAPI.Authenticaiton.Status != TumblrAPI.AuthenticationStatus.Valid)
                throw new UnauthorizedAccessException("Incorrect Tumblr credentials.");

            Console.WriteLine("Now make some posts...");

            //Get the DasBlog XML files, they are like <entry><title/><content/></entry> and stuff
            XNamespace ns = "urn:newtelligence-com:dasblog:runtime:data";
            var posts =
                from file in DirectoryInfo(@"C:\overheardathome\xml").GetFileSystemInfos("*.dayentry.xml") 
                orderby file.Name
                from entry in XDocument.Load(file.FullName).Root.Descendants(ns + "Entry")
                select new TumblrAPI.Post.Text{
                    Title = (string)entry.Element(ns + "Title"),
                    Body = (string)entry.Element(ns + "Content")
                };

            foreach(var post in posts){
                Console.WriteLine("  Response from text post: {0}", post.Publish());
                Thread.Sleep(500); //Tumblr will API limit me if I bash on them.
            }

            Console.WriteLine("Done, press any key...");
            Console.ReadKey();
        }
    }
}