If the arrival of Google Voice to the iPhone got you a bit excited, here’s another announcement that may please you. This time it’s from the folks at Twitter, who have announced that they have updated the official Twitter for iPhone app. The app is now officially on version 3.2.1, and with the new version comes push and SMS notifications for @mentions. Once enabled on your account, you will start receiving SMS and push notifications whenever a Twitter account you follow mentions you on their tweets.

Twitter is the latest thing in social networking. Think of it as a micro-blog. While the Twitter website offers a basic interface for posting “Tweets,” a ton of clients (both for iPhone and desktop) as well as web apps have flourished, and we’ll be taking you through them, letting you know what features and drawbacks you can expect to find.