Digsby, the instant messaging, social networking, email super-tool we first told you about last month launches its public beta today. That means you can sign up without an invitation code. The latest version of the Digsby client also has ton of new features:

• Twitter support
• Audio and video chat through a partnership with ToxBox
• Spell checking
• New "listening to..." status box will automatically update your status with currently playing songs from iTunes or Winamp
• Block contacts by right clicking in the IM window

If you're still not exactly sure what Digsby does, it's basically a single application that lets you communicate with your IM contacts, friends on Facebook, MySpace, or Twitter, or anyone else thanks to email notifications. You can configure Digsby to display a pop up alert every time you receive an email, every time a friend sends a message via Twitter, or every time someone changes their MySpace or Facebook status. You can also see a list of recent updates in each category.

Digsby historically has been a bit of a memory hog compared to lighter weight instant messaging programs like Pidgin. But considering just how many features Digsby has that Pidgin lacks, the memory use doesn't seem excessive.

The application is available for Windows XP and Vista. Mac and Linux clients are in the works.