Interesting web site of the Barna Institute...long time Christian run, religious life /practice researchers. George Barna has recently written a book called Revolution about the changes in the landscape of the church today.
Here's a snippet from the web page:
Rapid Increase in Alternative Forms of The Church Are Changing the Religious Landscape
Americans are creating new forms of religious experience and expression that are replacing the common approach (i.e., attending events and programs at a congregational form of a local church). During the last couple of years, in particular, there has been an explosion of activity in new forms of faith activity, such as the house church, marketplace ministries, and cyberchurch participation. The adherents of these new forms of the Church span the demographic spectrum.
More at:
http://www.barna.org/FlexPage.aspx?Page=home