PCWorld recommends ecto for MacOSX
Ecto costs [almost] $18, a slightly lower price than the other programs I tried. And its support for titles in Blogger is a significant advantage. Provided you've already got a blog set up, Ecto is what I'd suggest for composing and posting efficiently.

[From PCWorld.com - Mac Skeptic: Be a Blog Author]

Don't forget that ecto for MacOSX also has support for Amazon, Technorati tags, del.icio.us bookmarking, scripting (not only AppleScript, but also Perl, Python, etc.), Automator actions, iPhoto import, image manipulation, WYSIWYG editing, and so on.

And the Windows version of ecto is getting better and better as well.

Posted by Adriaan on June 04, 2005