Nimbuzz: One contact list, all account.
Nimbuzz is another all in one chat client available for free. All in one means that if you have several chat client such as Skype, Windows Live Messenger (MSN), Yahoo Messenger, ICQ, AIM, studiVZ, GoogleTalk, Facebook, MySpace, Jabber and many more. You can log in at one time through Nimbuzz.
Its function is similar to Meebo because it is a webbase platform, but Nimbuzz have a mobile service means you can use it via phone or mobile devices. With its mobile, Web, Wap and desktop clients, Nimbuzz is available on thousands of the worlds’ most popular devices across all major platforms – Symbian, iPhone, iPod touch, Windows Mobile, Android, BlackBerry, J2ME, as well as Windows and Mac desktop computers. Wah!
Nimbuzz also have NimbuzzOut, where you can use your mobile phone to make call to landline or mobile phone (international calls) at economical way. For example if I use Celcom for IDD call to Turkey, it cost me RM1.50 per minute. With NimbuzzOut, it only cost me USD0.033 or approximately RM0.12. Skype will charge at USD0.034 and charge block is rounded per minute.
Good alternative for Skype, and Celcom 
huhu..seems good. I believe it will help me a lots.