I recently had a student who had to qualify in English for an au pair position in the USA. We didn't have much time to get her ready and it occured to me that conversations I have with family in the USA on skype.com might be something that could augement her conversation skills. I didn't have to leave my home, and though it's a bit difficult to "teach", it is helpful in the conversation arena.
She's normally a bit shy and it takes a while during the teaching session for her to "warm up" as far as speaking goes. I was amazed to discover that she was more relaxed on screen than face to face. I have used it with another lady who is going to hook up with her hubby stationed in another country. She's a French speaker and he is British and a French speaker. Her desire was to be able to speak to her husband in English, teach their 3 year old son English so that reunions with her husband's family in the UK would be more satisfying. She has another younger daughter and sometimes lessons were a bit discombobbled with interruptions from the children. We were able to have conversation sessions on skype after the kids went to bed. Again, a special need situation. It has made me more flexible however, and I am able to meet my student's needs and help them arrive at their goals in another way.
Since skype also allows for conference calls, I invision the possibility of a few people at once being able to converse. Not the optimum, but helpful when scheduling becomes an issue.
Don't know if this helps anyone out there, but for what it's worth, it has been a good experience for me.