With cell phones you can share your opinions in short and let each other know your point of views on a topic. Later you can go on Skype, going in more details. You can pursue the follow-ups of your conversations through email.
You can add people in a group on Skype; so can you can form a group in an email account such as Gmail. You can add or delete people as you like. The main idea is to work with a team of people to solve world problems.
Microsoft software development