Windows | Mac OS | Linux
This add-on for Firefox is a perfect tool for posting entries to just about any blogging software or service in existence.
TweetDeck
Windows | Mac OS | Linux
Don't restrict Twitter to just a column when this Adobe Air–based software can spread itself across your desktop with multiple columns. Each column can contain replies, direct messages, or whatever you specify. As with any tweet tool, the columns auto-update as new tweets arrive. TweetDeck stores all tweets that arrive while the app is running so you don't miss anything overnight.
Twitteriffic
Mac OS| Mobile
A small desktop footprint is the hallmark of this reverse-type Twitter app, great for reading and posting to the popular microblogging service. All the features you expect, and more, are there—even in the free version, which includes advertisements.
Zooundry Raven
Windows
Finally, standalone software that gives Windows Live Writer some serious competition for the pro bloggers. It handles full WYSIWYG editing on multiple blogs and can run portably from a USB flash drive to use with any Windows PC.
Twhirl
Windows | Mac OS
A desktop interface for Twitter, twhirl requires Adobe AIR to run but makes it infinitely easier to keep up with tweets and/or twits.
Ustream.tv
Web
Still the best way to broadcast yourself, live, across the Web. All you need is the webcam.
WordPress.com
Web
You could install WordPress on your servers, or go right to this commercial, hosted site and set up a professional-looking blog in no time.
Read our review of WordPress.
Windows Live Writer
Windows
This desktop software for blog posting is a favorite with the pros who want a WYSIWYG editor that also posts photos, maps, and other content.
Source: http://www.pcmag.com/