Some of the biggest hesitations
people have about purchasing Apple's iPhone when it is released this summer is Apple's exclusive deal with AT&T/Cingular. For some people this presents problems about coverage in specific areas, but for many the problem is that switching to AT&T/Cingular will require early termination of an existing service agreement with a different carrier. Almost all cell phone companies in the US require users to sign one or two year commitments and pay fees in the neighborhood of $200 for breaking those commitments.
Fighting to be let out of an agreement is difficult in the best of circumstances. In many cases, even having valid issues with the carrier won't make getting out of the contract easy. Transferring the contract to someone else may actually be the best option for customers looking to ditch their current provider in order to purchase an iPhone.
Web-based services Cell Swapper
offer match-making services for transferring service agreements. For a fee, both sites will attempt to match a consumer looking to get out of his or her service agreement with someone looking to purchase service without signing a new full-length agreement - typically someone trying avoid an activation fee or looking to avoid signing a new lengthy service agreement. Users of both sites are free to negotiate or offer incentives such as an existing phone, cash, or other terms as part of the transfer agreement.
The process of transferring a service agreement appears to vary between carriers as does whether carriers will allow users to port their existing phone number. Some carriers consider the actual phone number to be tied to the contract while other don't. Both sites provide information to aid in the transfer process.