The mobile phone company unveiled the C190 and the NAITE last week. To publicise the launch, a live webcast was masterminded by digital PR specialist Wolfstar.
The new phlogging tool ipadio was used to field live questions and comments from people across the globe, with responses from senior figures at Sony Ericsson.
Micro-blogging site Twitter and video platform Kyte were also used in the live broadcast, which received 5,500 hits in the first six hours.
A spokesman for ipadio said: 'The use of the three media together is pioneering. It gives people the choice on how they would like to communicate.'
Sony Ericsson V-P and head of external comms management Merran Wrigley said of the campaign: 'We needed to start at the beginning of our story in order to gain credibility with a green audience. We used digital to generate and keep the buzz online.'
Meanwhile, Wolfstar founder and MD Stuart Bruce pointed out that such digital-only launches were more environmentally friendly than traditional media launches.
The two green phones have casing made from recycled plastics, less packaging and reduced toxins in the batteries.
The first of the two phones, the C190, will be released in shops at the end of June. Sony Ericsson launched its Green Heart initiative in September last year to encourage people to recycle their phones.