[Air-L] online community statistics

Hello all, I was wondering if anyone out there has any citations for updated statistics/estimates of the number of Internet users who use online communities. The most current estimates I can find are from a 2001 Pew Internet & American Life report that indicate that approximately 100 million American Internet users have used an online community. Any help would be greatly appreciated! Thanks in advance! Lorraine Buis, PhD Postdoctoral Research Fellow Veterans Affairs Health Services Research & Development