Yahoo Messenger 7.0 has had audio-chat for some time, but the walkie-talkie feature of the past--where one user had to stop talking for the other to start--has been replaced with a persistent connection that lets people talk over each other. The calling, strictly PC-to-PC, Yahoo Messenger-to-Yahoo Messenger, is free, and requires a headset, or microphone and speakers. Also new to the 7.0 beta is free voicemail and a call history log.
Other new tools and features include drag-and-drop photo sharing, tighter integration with Yahoo 360, the portal's still-in-beta blog and social community service, and defenses against "spim," or IM spam.
The move comes on the heels of American Online rolling out a test version of its instant messaging client, AIM, that offers improved PC-to-PC calling, and Microsoft updating its own client, MSN Messenger, with beefed-up video conferencing.
Yahoo Messenger 7.0 can be downloaded here.