This is something I've wanted to implement in the Massive Tool for some time, and I finally have a provisional method for doing it. If you
Selecting the "Post to LiveJournal!" command will open up LJ's update page in a new window, with the text from the Massive Tool already inserted into the appropriate field. All you need to do is select your icon/mood/tags/whatever, as needed, and then hit the button to post to your journal. If you right-click on the Toolbar button, you'll get a screen allowing you to enter the subject, select your mood, and so forth – all of which you can already do just as easily on the LJ update page; but I've created that separate screen so that (eventually) you'll be able to define various defaults and so forth.
Because of the way that Delphi/Windows works, the new browser window which is opened will recognize Internet Explorer cookies, regardless of what your default/usual browser is. If you have logged onto LJ from IE (with the "Remember me!" option to set cookies) then you'll already be logged on when this screen opens. The Massive Tool itself, at this time, does not request or access your username or password in any way; it just opens up the browser which may or may not already have that information.
I've tinkered with quite a few other things in the program since the last update. I'll discuss some of the others in future posts; but this one is the biggest and the one I wanted to get out there.