w.bloggar is a popular blog posting tool which supports just about every blog engine out there (including .Text, which I use). It's got a nice user interface and is regularly updated. Version 4.00 has been in the works for a while, and was just released today.
The one thing that's annoyed me about previous versions is that it doesn't let me directly edit the HTML. It lets you type in HTML tags, but it does some funny business with them, such as convert carriage returns to <p> tags. I used to use it, but have recently been using IMHO (which I'm quite happy with).