Adium - If have a URL copied to your clipboard, Adium suggests this automaticly when you want to insert a link.
Skype 5.0 for Mac - Displays an arrow next to a person’s mood message. When clicking on the arrow, all links will be opened at the same time.
Chrome - Status bar shift down with the cursor when it is hovering a link near the bottom of the page. After a few seconds its hows the entire URL.
Chrome - After you copy a URL from the navigation bar, it automatically adds http:// in front of it when you paste it somewhere else.
Tweetdeck for Chrome - Toggle between full and shortened URL’s by clicking on the link.
/via Miguel de Leon
Twitter for Mac - Character counter treats url’s as shortened url’s
When used in direct messages on the site, Soundcloud turns internal URLs into proper links with useful descriptions.
Tumblr - while creating new blog the form field is already filled in and your entry aligns to the right of the form