I am on a $79 Telstra NextG Cap
That gives you $450 worth of voice & sms to fixed lines and mobiles
An extra $100 worth of voice calls between Telstra mobiles
I was on a $60 plan on the iPhone but went into a T-Shop last week & successfully swapped over to the $79 cap - just had to pay the 'ETC' (Early Termination Charge) from my old plan/contract as I had a further 14 months to go (was less than $500)
I also spend an extra $10 on a datapack which gives 150mb worth of data.
That combined with internet tethering between my laptop via USB or Bluetooth makes for a versatile on-the-go mobile broadband platform
After owning an iPhone for the last 10 months I would NOT go near any other smartphone ... EVER .... PERIOD. It is just far too good