According to my promise i am come back with trick to change your iPhone as a Wi-Fi Hotspot. I found good response with first part.My second part is the last part of this trick and also totally complete.
STEP A: First Install the Jailbreak in your iPhone and follow next steps.
STEP B: Jailbroken phone is up and runing then launch the Cydia application store.
STEP C: After launching the Cydia,Search for "MyWi",Here two apps listed,one says"No Rock" next to it never installed for us.Grab (Catch) the other one instead.
STEP D: Tap the install button and tap the confirm when installation complete then tap the "Reload Spring Board" button.
STEP E: Launch the MyWi apps and accept the agreement and Tap OK.After some time apps work and we got it working
. It appeared as if the problem was with registering for a RockYourPhone account via the app.
STEP F: Instead of registering a account by apps,we go to
RockYourPhone.com and signed up.
STEP G: Re-launch MyWi. Tap "sign in." Paste in your email, type in your password. The app will check for your registration.
STEP H: you do get the app to launch, you'll see the option to turn Wi-Fi Tethering on via a toggle switch at the top. You can also turn on USB and Bluetooth tethering using the toggle towards the bottom. With tethering on, your phone's Internet connection, 3G or otherwise, is made available as a Wi-Fi hotspot to nearby computers.
STEP I: When you're finished, you can switch tethering off and close the app.
STEP J: If problem come in sharing the 3G Data Connection,Go into the Settings app -> General -> Reset -> Reset Network Settings. Reboot the phone and try MyWi again.