There are lots of different approaches to the amorphous market of 'e-learning' but only a handful ever feel much like fun. I think amongst the best of these are sites like MangaHigh which teaches Math, or Moshi Monsters which has subtle learning tasks for kids.
Another which works well is Quipper
I have started this blog to keep track of all the interesting stuff I read about. In some cases, friends of mine have shared their cool stuff with me. I try to keep the headlines and descriptions short, so you must follow the links to read and decide for yourself if a topic is worth your time. Want to contribute? Just comment on any of the stories and I will be notified instantly.