Tweetily

Does not only tweet newly published posts, but goes back in time and retweets all blog posts again.

Based on the Tweet Old Post WP plugin.

Installation:

Unpack and upload it to the /wp-content/plugins/ directory.
Activate the plugin through the 'Plugins' menu in WordPress.

What is new in this release:

• Updated to use Twitter's new API connection.

What is new in version 3.1:

• Minor bug fixes and improvements.
• Tweaks for GoDaddy hosting accounts.
• Tweaks for multi-author blogs.

What is new in version 2.3:

• More code cleanup.
• Removed testing code that caused problems with some Web hosts.

What is new in version 2.0:

• Re-worked the Twitter authorization system.
• Added updated queries for those running W3 Total Cache.

Requirements:

• WordPress 2.7 or higher