Knowledge and Web mining
The application of data mining techniques to the content, structure and usage of Web resources
Usage mining e.g. Amazon personal recommendations (note privacy issues!)
Structure mining e.g. RDN-WSE project http://ilrt.org/discovery/2002/01/wse-rdn/
Content mining (data) e.g. AstroGrid developing a virtual observatory to support explotation of key astronomical datasets http://www.astrogrid.org/