I have been working on a plug-in for Lightroom to export pictures to Day One. I was annoyed that I had to export pictures from Lightroom and then import those pictures into Day One, so I decided to create a plug-in that automated the process for me. The plug-in is still in development, but it is coming along nicely. For more information or to download and use it, you can go to the github page. Feel free to let me know if you run into any problems.