1. A method comprising: storing bonds that reflect relationships between searchable items; wherein the searchable items include a plurality of documents; wherein the bonds are not stored as part of the searchable items; wherein the bonds do not reflect storage location relationships between said searchable items; receiving a search request to perform a search for searchable items that are associated with a keyword, wherein the search request specifies the keyword; determining that a particular searchable item is to be the starting point of the search; responding to said search request by performing the search relative to the particular searchable item that is to be used as a starting point for said search, wherein performing the search includes at least one of: (a) ranking documents that match said search based, at least in part, on the minimum number of bonds that have to be traversed from the particular searchable item to arrive at each document, wherein the documents that match said search include a first document and a second document, wherein the minimum number of bonds that have to be traversed from said particular searchable to arrive at said first document is different than the minimum number of bonds that have to be traversed from said particular searchable item to arrive at said second document; (b) searching against documents that are within one bond of said particular searchable item; and if the number of documents, within one bond of said particular searchable item, that match the search is less than a target number, then expanding the search to documents that are within two bonds of said particular searchable item; and repeatedly expanding the search to documents that are one further bond away from the particular searchable item until at least the target number of documents that match the search have been identified; or (c) sequentially performing a series of searches relative to said particular searchable item until a predetermined maximum number of bonds from said particular searchable item has been reached, wherein the series of searches includes a first search and one or more subsequent searches, wherein each search of said one or more subsequent searches is performed against documents that are at a greater minimum number of bonds that have to be traversed from said particular searchable item than the documents that were searched in any search that preceded said search in said series; wherein the method is performed by one or more computing devices.