21. A system for building, managing, and sharing a searchable personalized database, the system comprising at least one processor and one or more modules for: enabling users with personal computers having a local storage system and access to the Internet to create selectively shareable personalized databases of a plurality of selected source files, including files originating from the user's local storage system, files located in access-restricted databases, accessed through the Internet, to which the users have obtained personalized access permission, and selectively shareable files the users create; enabling users to annotate files in the their personalized databases and incorporating those annotations into the personalized databases; generating one or more word level inverted indices of the personalized databases to support text searching of database source files and in-context highlighting of search terms during display of database source files; enabling users to register selected ones of a plurality of selectively shareable personalized databases; enabling users to unregister selected ones of a plurality of selectively shareable personalized databases; selectively searching registered ones of the plurality of personalized databases, using the one or more indices, according to a search criterion, to locate words and phrases in the source files of the registered databases; and sending information for the display of at least portions of files in the plurality of selected source files that meet the search criterion with in-context highlighting of search terms consistent with the search criterion.
21. A system for building, managing, and sharing a searchable personalized database, the system comprising at least one processor and one or more modules for: enabling users with personal computers having a local storage system and access to the Internet to create selectively shareable personalized databases of a plurality of selected source files, including files originating from the user's local storage system, files located in access-restricted databases, accessed through the Internet, to which the users have obtained personalized access permission, and selectively shareable files the users create; enabling users to annotate files in the their personalized databases and incorporating those annotations into the personalized databases; generating one or more word level inverted indices of the personalized databases to support text searching of database source files and in-context highlighting of search terms during display of database source files; enabling users to register selected ones of a plurality of selectively shareable personalized databases; enabling users to unregister selected ones of a plurality of selectively shareable personalized databases; selectively searching registered ones of the plurality of personalized databases, using the one or more indices, according to a search criterion, to locate words and phrases in the source files of the registered databases; and sending information for the display of at least portions of files in the plurality of selected source files that meet the search criterion with in-context highlighting of search terms consistent with the search criterion. 37. The system of claim 21 , wherein the one or more modules enable users to create databases further enables them to create databases without creating extraneous copies of files.