when streaming video, it can be quite hard to find a good balance between quality and a good connection. sometimes you are also confronted with bottlenecks by international connections.
video streaming seems most effective in workshops that do not concern software.
tools to check out:
quicktime broadcaster (propietary) www.apple.com/quicktime/broadcaster/
darwin streaming server developer.apple.com/opensource/server/streaming/index.html
wirecast (not free in any way) www.varasoftware.com/products/wirecast/
for max and pd users there are also several objects such as jit.qt.broadcast, see the usual repositories.
we did a workshop on this specifically: