I worked in IT support and currently retail. Never thought I would end up in either of these two positions but well, they helped me overcome anxieties about my mild stutter. It'll happen, I'll have really long day and feel extremely self-conscious each minute but most people don't care. They forget the interaction and move on--it's not like high school where gossip spreads like wildfires. I'll talk my freaking head off if need be and those few stumbles in-between are forgiven or ignored in the overall context. Stuttering, accents, dialects, lisps, and whatnot are all common things that deviate from whatever "perfect" voice is embedded in mind. The more you communicate with people, the truer this becomes and hopefully the less you feel you need to hide or hold back. Phone skills mostly mean you can sell something--some are swayed by a slick talker, others by knowledge or personality. I wouldn't sell yourself short out of these jobs because you may end up doing only a few calls and placed elsewhere that matches your own set of skills.