The new Yahoo Instant Messenger with Voice, which offers telephony functions, features more than 180 plug-ins created by developers from inside and outside Yahoo.
Video: One-stop Web communications shop
CNET's Elsa Wenzel takes a look at Yahoo Messenger with Voice 8.
"Yahoo Messenger is being used in ways it never was in the past," said Jeff Bonforte, senior director of real time communication at Yahoo.
For example, a plug-in called Yahoo Avatar Space lets people interact with their avatars, change the avatars' mood and customize the space with different decors and images from Yahoo Image Search.
A Yahoo Movie Trailer plug-in lets people scroll through current movie trailers and watch them within the plug-in or in full-screen while IMing with a friend. Another plug-in, Yahoo Finance, lets people track stock and recommend stocks to friends.
Other plug-ins include Pando, which allows fast file sharing; YEmote, which lets users access secret emoticons; Yahoo Greetings eCard, which enables a user to send an e-card while chatting; and Eazibo, which lets people make flow charts and diagrams and share photos.
Yahoo introduced the beta of Yahoo Messenger with Voice last month.
Two weeks ago, Yahoo and Microsoft made their IM services interoperable. The companies will eventually enable voice interoperability as part of the partnership, Bonforte said. No time line has been set for that yet, he said.
Yahoo isn't the only one beefing up its instant-messaging platform. Last month, Microsoft launched Windows Live Messenger, which automatically updates contact information and lets people share files by dragging and dropping files onto a contact list.
AOL recently introduced a free AIM phone service, and Google's Google Talk entered the fray with text chat and computer-to-computer voice connections.