23. A computer-readable memory device that stores computer-executable instructions, the computer-readable memory device comprising: one or more instructions to search a collection of documents, based on a search query, to identify a set of search result documents; one or more instructions to receive a request to save a selected search result document of the plurality of search result documents; one or more instructions to save information associated with the selected search result document in response to the request to save the selected search result document; one or more instructions to identify a particular document that is similar to the selected search result document based on the saved information and, where the one or more instructions to identify the particular document that is similar to the selected search result document includes at least two of: one or more instructions to determine whether the particular document and the selected search result document have a plurality of outgoing links that point to the same documents, one or more instructions to determine whether the particular document and the selected search result document have a plurality of incoming links that come from the same documents, one or more instructions to determine whether the particular document and the selected search result document have a same format, or one or more instructions to determine whether the particular document and the selected search result document have a same layout; and one or more instructions to boost, based on saving the information associated with the selected search result document and identifying the particular document as similar to the selected search result document, a score for the selected search result document and a score for the particular document for subsequent searches involving the search query.
23. A computer-readable memory device that stores computer-executable instructions, the computer-readable memory device comprising: one or more instructions to search a collection of documents, based on a search query, to identify a set of search result documents; one or more instructions to receive a request to save a selected search result document of the plurality of search result documents; one or more instructions to save information associated with the selected search result document in response to the request to save the selected search result document; one or more instructions to identify a particular document that is similar to the selected search result document based on the saved information and, where the one or more instructions to identify the particular document that is similar to the selected search result document includes at least two of: one or more instructions to determine whether the particular document and the selected search result document have a plurality of outgoing links that point to the same documents, one or more instructions to determine whether the particular document and the selected search result document have a plurality of incoming links that come from the same documents, one or more instructions to determine whether the particular document and the selected search result document have a same format, or one or more instructions to determine whether the particular document and the selected search result document have a same layout; and one or more instructions to boost, based on saving the information associated with the selected search result document and identifying the particular document as similar to the selected search result document, a score for the selected search result document and a score for the particular document for subsequent searches involving the search query. 24. The computer-readable memory device of claim 23 , further comprising: one or more instructions to receive another search query; one or more instructions to determine a second set of search result documents based on the other search query, where the second set of search result documents includes the selected search result document and the particular document; one or more instructions to rank the selected search result document and the particular document within the second set of search result documents based on the respective boosted scores for the selected search result and the particular document; and one or more instructions to present the second set of search result documents, including the ranked selected search result document and the ranked particular document.