A contract is a contract, though, and those ETF fees can be quite unpleasant, especially with the convoluted terms the carriers are binding you. If you wonder how much will the whole Verizon-rocks-man-I-love-me-iPhone undertaking cost you, there is a handy calculator posted by user MM over at the scientific search engine Wolfram Alpha. It prorates the ETF in accordance with how many months you have left of your contract, and also takes into account the doubling of the Early Termination Fee that AT&T introduced on June 1st.
The ETF calculation widget is embedded below for your convenience, and if you have just bought an iPhone last month, the divorce with AT&T will run you the cool $315.
source: WolframAlpha via MobileCrunch