Yahoo gives users a preview of what it will be like to use a new and improved version of Yahoo Messenger on Microsoft's Windows Vista at CES Show this year.

Yahoo will show off an early version of Yahoo Messenger optimized for Vista, with new features that take advantage of some of the user interface enhancements Microsoft has added to the OS.

"It feels very much at home as though it's living and breathing in Windows Vista," said Joshua Jacobson, a Yahoo senior product manager, of the version of Messenger built for Vista. The company plans to release a beta of the application in the second quarter of 2007, and a final version should be available four to six weeks after that, pending feedback, he said.

Windows Vista is already available for business users, and is expected to be available to consumers on Jan. 30.

Yahoo used the new GUI (graphical user interface) development framework in Vista called Windows Presentation Foundation (WPF) as the basis for several of the new features of Messenger. New abilities to scale up in size the avatar and contact information for people in a user's contact list, a color wheel that allows users to choose a new color for Messenger's skin, and a feature that shows a large-sized emoticon that goes beyond the boundaries of the Messenger window before shrinking to its normal size all use WPF, Jacobson said.

Yahoo also has added a feature called Yahoo Show and Tell that allows users who are connecting via voice on Messenger to share photos so they can converse or send IMs (instant messages) about them while they are talking. Eventually, Messenger will allow users to share videos this way as well, Jacobson said.

Another new feature in the Vista version of Messenger follows the lead of both Internet Explorer 7 -- the browser included in Vista -- and Mozilla's Firefox browser. Like those applications, which allow users to create tabs for new browser windows to more efficiently keep track of where they are surfing, Yahoo Messenger will do the same for instant messages, Jacobson said.

The application does not automatically create tabs as some IM software does, however; it lets users create the tabs themselves so they have control over which conversations they would like tabbed, he said.

Finally, Yahoo has added a new "voice visualization" feature to Messenger that lets Vista users see their voice on the IM window coming through as a visual sound wave, Jacobson said. This will help let them know if the person they are speaking with can hear them and if their voice is at an appropriate volume level, as well as to make the connection between users a more "intimate" experience, he said.

Yahoo will be exhibiting at CES, which is being held this week through Thursday in Las Vegas.