Cellular Data and Battery life

the problem with the iphone 4s is that 3g is eveytime on and you CANT turn it off like in the 4 or swich erverytime like in the 4 that will take a lott of batterielife

Anytime the phone sends or receives a signal, it is using battery power. Transmitting and receiving requires power.

You can leave wifi on and just turn off the setting to "Ask to join networks". It then does not continually scan for available networks. It will join known networks as it periodically will look just for those. And you can manually join a network at any time. I leave my wifi like this all the time, and having it always on like that makes almost no difference to battery life versus turning it off.

Cellular data - you are right that turning it off really saves nothing, as the cellular radio is checking for the carrier signal all the time anyway (it actually does this many times per second, but powers off the cellular radio inbetween to save power - a scheme used by cell phones for decades since just keeping the radio powered up all the time uses a lot more power). The phone will only actually use additional power if send or receiving cellular data, but just being on and available for data uses no more power than having it off really, since cellular data off does not equal cellular radio off.

If you use push mail (and get a lot of email) and a lot of notifications (especially ones that repeat frequently), if outside the range of any wifi, the phone will use 3G data for those services, so it can run down the battery rapidly. But that is not really a function of having cellular (or 3G) data on or off, it is a function of how you have your accounts and notifications set up.