13. A non-transitory machine readable medium containing executable computer program instructions which when executed by a data processing system cause said system to perform a method to organize information in the data processing system, the method comprising: determining a mathematical representation of a document, wherein the document is an electronic mail received through an electronic mail system, wherein said document is not part of a collection of documents; comparing said mathematical representation of said document to a collective mathematical representation of the collection of documents; and categorizing said document as being associated with said collection based on said comparing, wherein the content of said document is not known to a user of said data processing system upon said categorizing.
17. A medium as in claim 13 , wherein said comparing comprises: determining a similarity indicator from said mathematical representation of said document and said collective mathematical presentation.