Technology is redefining the scope of learning . Just in time learning is become more common place. The human society is moving in a lighting speed to a zone where learning would become as pervasive as it can. In future we could have robotic angels who would deliver us whatever we want to learn at any point of time.
Until we reach there, there is WiZiQ, an educational auction service from Educomp, which helps teachers to offer there services to the students. Its free . Earlier there was dimdim which had also the integrated conference framework which was also free, compare to WebEx .I have used WebEx , I have used DimDim and also WiZiQ . I could only say the things are really getting better and better, in the syncrhonous elearning space .
Lately , there was also concept of Semantic learning and Mobile learning . I published a research proposal on semantic learning 2 years back , when people where not talking about semantics so much as it is now . The paper was published by idealist.
At, that point , I conceived about the same angel, who would, deliver us whatever we want to learn at any point of time, through the semantic web reskiller.