From Elixir Graphics:
Thurly is a plug-in for Safari that allows you to both shorten URLs in a snap as well as post directly to Twitter without ever leaving your browser window. With a quick keyboard shortcut (Command-Control-T) Thurly springs to life automatically shortening the URL of the web page you are on.
From there you can copy the shortened URL out to use elsewhere. Paste it into emails, forums posts, blog entries and much more.
Thurly allows you to also post to Twitter from the main interface. It populates the Status field with a shortened URL and let's you edit your post as you like. Click "Tweet" or press Command-Enter and your post lands in your Twitter updates.
Registering Thurly is not required. You can use the base features of the plug-in, shortening URLs and posting to Twitter, for free until the cows come home.
We have added some bells and whistles though to make your life easier. Registering allows you to use multiple Twitter accounts, letting you post from different accounts on the fly from the main interface.
We have also built in the option to use a Twitter template. The template let's you set a default message that appears in your Twitter Status field each time your open Thurly. Which can also be overridden at any time.
Added ability to define shortcut keystroke with which to open Thurly. This options resides in the preferences.
Fixed bug which caused Safari to crash for a very limited group of users during its first launch.
Added contextual menu to both the Twitter Status field and Template field which allows users to easily insert variables.
Improved version checking.
Added %title% variable for use in Twitter Status field and Template that inserts the site's title. Title is pulled from the web page's title tag.
Added the ability to write posts that are longer than 140 characters long. Thurly disallows user from Tweeting message until the post has been trimmed down to 140 characters however.