I was complaining limitations and shortfall of the iPhone 3G.
After extensive googling, I decided to jailbreak my iphone.
I have tried a few attempts that I was not able to, and found out that OSX 10.5.6 running on my Macbook is the culprit not allowing my iPhone to turn to programming mode, aka DFU mode.
However, there were discussion with the following solutions:
1. downgrade OSX from 10.5.6 to 10.5.5 - a big NO to me. 10.5.6 is very much stable and responsive, I will not downgrade just to jailbreak my iphone;
2. get a Windows PC and do the trick. Well I cannot get the tools to run on Windows properly, it crashes;
3. use a USB hub to connect between iPhone and Macbook. I used the USB hub built onto our HP LCD monitor, and have it connected to the iphone and macbook, and it works!
After jailbreaking the iphone, I have installed biteSMS, solved most of the SMS issues that Apple left out, i.e. SMS forwarding, deleting individual SMS instead of the whole conversation.
Another app cannot be missed is SwirlyMMS, the only MMS application for the iphone.
lastly, I installed SIAX, the VOIP client capable of SIP and IAX connectivity, and claimed able to make call even over 3G network, as oppose to Fring and Truphone that seems restricted by Apple to allow SIP call over 3G network.