I switched from Sprint, and didn't have to pay an early termination fee even though I just renewed my contract back in April for another two years (after buying a Motorola Q which I'm not going to ebay.)
My previous bill highlighted a section stating that beginning August 1st, Sprint was upping their roaming rates by 20 cents. Since this was a change of the contract on their part, I took it as a sign and an opportunity to escape Sprint and go with iPhone/AT&T.
I ended up spending around an hour on the phone, first with a 1st tier customer service rep, then with an account services rep who denied my request stating that I didn't use roaming hardly at all. How could it adversely effect me, she wanted to know. I just kept repeating, "you changed the contract. I want out, and I don't want to pay an ETF." She finally said she wouldn't do it, so I asked to speak to a supervisor, grumbling that I'd been a model customer for 10 years, and why would they want to bilk even more money out of me, blah blah blah... much to her annoyance. She claimed the supervisor would only say the same thing she had said to me, but I pressed her to allow me to speak with the supervisor anyway.
During the period I was on hold waiting for the account reps supervisor, I looked up Sprints terms and conditions and found the appropriate section detailing breach of contract (honestly, something I should have had ready from the outset of the entire phone call.) Once the supervisor came on the phone and began giving me the same spiel as the previous service rep, I whipped out the pertinent section of the terms and conditions, reading it to her word for word.
I said, "In section 1-2 of your terms and conditions on your website, it states '...if a change we make to the Agreement is material and has a material adverse effect on you, you may terminate each line of Service materially affected without incurring an Early Termination Fee only if you: (a) call us within 30 days after the effective date of the change; and (b) specifically advise us that you wish to cancel Services because of a material change to the Agreement that we have made.'"
After I read that to her, there was no other discussion. She said my service would be terminated on August 2nd (a month from the day I made the call), and I would not have to pay an early termination fee. I told her "thanks," got her name, made sure it was in her notes, and hung up.
The draw for me was that I was an existing ATT customer. I didn't need another phone but after all the hype and cool videos, I decided to take advantage of being a first Bellsouth, then Cingular now ATT customer. I just added $20 to my existing cell bill.
I've been with ATT for the last 2 years. They have better coverage then Sprint in my area. If the iPhone had been released on another carrier, I likely would not have switched. I was however ready for a new phone and was looking at the BlackJack and decided to wait to check out the iPhone. What a wonderful device it has turned out to be and I'm glad I waited.