The EDU 2.0 sites recently passed the 250,000 total member mark, adding 40,000 new users in the last month. Their growth is accelerating, and at the current rate EDU 2.0 will pass the 500,000 and 750,000 member marks sometime in 2011.

EDU 2.0 for Business, which launched earlier this year, just passed the 2,000 member mark and is growing at 7% a week.