每个用户的界面上都有“chat now”,你可以用这个来跟他们聊天（除非他们已经设置不允许）。当然同时你也可以看用户的IM（例如：msn、skype等）设置（除非他们已经设置不允许任何人查看他的IM）

Actually, if your friends had registered their IM account, which was shown in their own profile, you can add their account to your contact list. To make things easy, you can also select italki's online chatting tool. Go to your friends list. At his/her personal profile page, you will see CHAT NOW option at the right-hand side of the page. Click on it and start the chat!

say anything you want. greeting first. how are you, how is going... some ppl say how are you today? what are you doing or what were you doing today? or weekend? then....creat new topic