What this means is that anytime someone in your tweet stream sends out a tweet from Foursquare (which, to the annoyance of some users, happens automatically at times), that Foursquare link (shown as a 4sq.com URL) will be able to be opened in Tweetie in a way that displays the location information in a nice format. When a tweet is eligible for this feature, you’ll see a purple square logo in the upper right hand corner of the tweet in Tweetie.

When you click on a Foursquare link, you’ll be taken to a page that shows the venue’s address and phone number as well as the Foursquare mayor of the place. If you click on the address you’ll load a Google Map showing you exactly where it is. If you click on the phone number, you’ll be able to call the place right from the iPhone. Below all of that, there is a button to open the venue in Foursquare, which launches the Foursquare iPhone app.

A couple other new features in Tweetie 2 include Vodpod video uploads and the ability to attach messages along with your TwitPics to that service.

Look for this Tweetie 2 update soon in the App Store (it will be version 2.1.1). Meanwhile, Tweetie Two for Mac should be released in a private beta in about a month, according to new info shared on MacHeist today. Tweetie for Mac will soon be added to the nanoBundle 2, and in anticipation, they’ve added this message:

As a MacHeist customer, you’re not only receiving a free upgrade to the upcoming, highly anticipated Tweetie 2 – we’ve also arranged exclusive access to the pre-public beta for you guys!

Have fun using the best Mac Twitter client for now… and stay tuned for an email from us in about a month with your invite to the future of Mac tweeting.