Yahoo! has released new version of its flagship instant messaging IM client Yahoo! Messenger with Voice beta, now at version 8.0.0.505. The main characteristic of new features in Yahoo! Messenger 8 is bigger and better, where the IM client now supports up to 1000 contacts and file transfers of up to 1 GB in size. In addition, software developer kit is available to allows users and programmers to develop plug-ins for Yahoo! Messenger. Previously, Yahoo! Messenger supported only maximum of 300 contacts and file transfers of up to 100 MB.

The main feature of Yahoo! Messenger 8 is the plug-ins capability for Yahoo Messenger. Plug-ins are free mini applications that can be easily added to the Yahoo! Messenger with Voice experience to personalize the messenger, or to enhance the feature of the messenger. Yahoo! also released its Application Program Interfaces (APIs) to encourage external and Yahoo! developers to build plug-ins for one of the largest consumer instant messaging (IM) communities worldwide.

With plug-ins, users will be able to take advantage of popular Web services right from Yahoo! Messenger with Voice. Some plug-ins that are installed by default are Yahoo! Music LAUNCHcast, Yahoo! 360° that allows to stay up-to-date on friends’ latest photos, blog entries, and reviews, and Yahoo! Answer. Other plug-ins available now including an Amazon.com plug-in that lets users share their Wish Lists with friends and family and an eBay plug-in to stay on top of their bidding activity throughout the day, in addition to plugins for iTunes, AmericanGreetings.com, Coupons, HedgeStreet, Jeteye, NewsGator, Pando Networks, 30Boxes, Yahoo! News, Yahoo! Calendar, Yahoo! Finance, Yahoo! Sports Gamechannel, Yahoo! Weather and etc.

Other features include ability to share pictures and files by dragging them into IM chat windows. Yahoo has thoughtfully added a contact search bar for those users who have hundreds of contacts. After sharing, your friends can click and view larger versions of your photos stored in Yahoo! Photos account, and both can save each other’s photos to your Yahoo! Photos account or to your computer.

Yahoo Messenger with Voice Beta version 8 also offers make free PC-to-PC Calls, and like other chat programs like MSN Messenger and Skype, Yahoo Messenger also offers both free and paid VoIP to call regular or mobile phones in the U.S. or in 30+ countries for 2¢/min. Interesting features are soundboard feature that allows people to add short sound effects into their voice conversations, including “audience booing” and “birds chirping” sound effects, and soundtrack feature where MP3 music files can be played as background music while talking via YM.

Other customary enhancements are ability to personalize the YM client with avatars, emoticons, audibles, custom ring tones, and more, and Yahoo! Messenger has also added the contacts search bar feature for those with huge list of contacts.

The beta version of Yahoo! Messenger with Voice is available simultaneously in 19 localized versions around the world including Argentina, Australia, Brazil, Canada, Canada en francais, China, France, Hong Kong, Korea, India, Italy, Germany, Mexico, Singapore, Spain, Taiwan, United Kingdom, United States and Yahoo! en Espanol. Standard version has the size of 11.5 MB.

Yahoo! Messenger with Voice is now able to communicate with contacts from MSN Messenger too.

Download Yahoo! Messenger with Voice Beta ( version 8 ) (Standalone setup install also available)

Update: Download Yahoo! Messenger 8.1.0.413