10. A system comprising: a processor; a data remembrance component; a display on which an indication of a first document is displayed, and on which said first document is viewable by a person; and a chooser that is executable on said processor, that is stored in said data remembrance component, and that chooses a second document from a document space based on said second document's having a sufficient level of dissimilarity from a set of one or more documents, said first document being among said set of one or more documents, said second document being displayed on said display after said first document as a result of having been chosen by said chooser, said set having more than one document, said chooser determining dissimilarity between said set of one or more documents and other documents in said document space by finding a centroid that represents content of said one or more documents and by calculating dissimilarity between said centroid and documents in said document space.
14. The system of claim 10 , wherein said set contains said first document and no other document, and wherein said chooser determines said level of dissimilarity between said set and documents in said document space by comparing said first document with document said document space.