Yep, it's time for an offline blogging client. I've heard good things about Windows Live Writer, so trying it out right now. It's got a feature where it analyzes the look (i.e. theme) of your weblog at install-time so it can give you an accurate preview of what your posts will look like. It at least got the sizes and fonts right!
Definitely seems cool so far, so we'll give it a run and see how it goes. Stay tuned for actual content next post.