For all iPhone and Blackberry users, I'm sure you are very familiar with these 2 applications. It's an application which allows users to communicate with each other in text messages for FREE. Forget about sms where you need to pay per sms, use Whatsapp and BBM (Blackberry Messenger) , you can chat all day and night for free. It's kinda like MSN messenger actually.
I've just got my iPhone for less than a month, and I'm already addicted to Whatsapp.
Since I'm an iPhone user, so I don't use BBM, but the Whatsapp function is actually almost the same with BBM.
There's advantages and disadvantages for everything. Seriously, nothing is perfect in this world. The advantage of these two application is of course, you can send text message to your friend(s) (who also own an iPhone and/or Blackberry Phone) for free. It really helps you to save a lot, if you are like me for one, love to text people. I actually saved up a lot by using Whatsapp, because I really text a lot in a day. Now that I'm using Whatsapp, I can bug my friends even more *evil grins* AND of course to keep in touch with them at the same time.
Here comes the disadvantage of it. It's not really a disadvantage if you didn't over-used it actually. For me, since I'm so used to Whatsapp now, when I received a SMS, I'll type one sentence, and STRAIGHT AWAY click the send button. Then, I'll go %#@^##. So, please be careful not to over-used and over-depend on it.