Windows, Linux, Mac (Firefox only): TinyURL Generator is a Firefox addon that once installed makes it really easy to create shortened URLs (using TinyURL.com) of any page you are currently reading.
After installation, it adds a little icon to the right end of Firefox status bar. While browsing any page, click on that icon to generate the shortened URL of that page. The icon will turn into a green tick and your shortened URL will be copied to the clipboard. Hit Ctrl + V and see your new shortened address.
This will be a great addon for regular twitters who use the Twitter’s web interface. As this addon automatically copies the shortened URL into clipboard, all one have to do is hit the icon and paste the URL into your mail client/IM window/browser.
Note that this is an experimental addon and hence will require an account at Mozilla addons to install. For those who do not have an account, we have uploaded the addon to box.net too.