23. The system of claim 1 wherein user preferences are used to assign a weight to one or more media objects represented by the sparse graph of media object similarities for adjusting one or more of the similarities.
23. The system of claim 1 wherein user preferences are used to assign a weight to one or more media objects represented by the sparse graph of media object similarities for adjusting one or more of the similarities. 24. The system of claim 23 wherein a weight for decreasing a similarity to other media objects is assigned a media objects having a negative user preference.