Valve has released a large Steam Client update that includes several new features. The update will be downloaded when you restart your Steam Client. The new features include:

• Guest Passes allow owners of certain Steam games (purchased either via Steam or at retail) to let their friends play games for free, for a limited time trial.
  
• Background client updates allows Steam to acquire new updates in the background and then (once they're downloaded) ask if you'd like to restart & apply them.
  
• Games list Favorites allows for organization of Steam games.
  
• Five Steam Skins to including Default, Ice, Sand, Obsidian, and Grey

Other updates include:

• Added 'next' button to Steam news window, allowing multiple messages to be viewed in a single session
  
• Fixed client attempting to update some games which user does not own; was occuring when user had played game during a Free Weekend
  
• Fixed games purchased via PayPal not working in offline mode

For more information and to see screenshots, visit the What's New page.