Found a decent application to publish articles on WordPress from the Ubuntu desktop: gnome-blog. Not too feature-rich but OK for quick posts. Available in Synaptic Package Manager.
Features:
- Simple to use interface
- WYSIWYG styled text support
- Panel popup allows entries can be written gradually over the course of a day
- Spell checking
- Drag and drop support for images
To install on Ubuntu:
$ sudo apt-get install gnome-blog
Webpage: gnome-blog