How to make Windows Live Messenger 8 communicate with Yahoo! contacts:
1. Go to Live Ideas and sign-in with your Live ID.
2. Download the latest WLM8 from here.
3. Install and have fun.
How to make Yahoo! Messenger 8 communicate with WLM contacts:
1. Go to this page, login using your Yahoo! ID and sign up for this beta.
2. Download the latest Yahoo! Messenger 8 with Voice from this page.
3. Install and have fun.
Enjoy cross chatting with your buddies from both the networks.
