Twitter, a free social networking and micro-blogging service, has changed the way many people communicate. Twitter allows users to send “updates” (or “tweets”; text-based posts, up to 140 characters long) to the Twitter website via short message service (e.g. on a cell phone), instant messaging, or a third-party application like Twitterrific or Facebook.

The updates are then displayed on the user’s profile page and instantly delivered to other users who have signed up to receive them. Users can receive updates via the Twitter website, instant messaging, SMS, RSS, email or through an application.

If you are both an iPhone and Twitter user, perhaps you’ll be interested in Twinkle –an iPhone Twitter client released last week. Critics say it’s better than the mobile version of Twitter, better than Hahlo, and better than MobileTwitter. It supports photos with your tweets, taken right from the iPhone camera, as well as geolocation. There is also a “Near Me” section that will show you other Twitter users in your area.

Unfortunately, Twinkle is only available on jailbroken iPhones. If your device fits the profile, just add “http://www.polarbearfarm.com/repo/” to your Installer.app sources list.

If you’re unfamiliar with Twitter or are bored with reading tutorials, B.E.T.A. Daily has put together a handy collection of videos that demonstrate various uses of Twitter.