Searching content in distributed computing networks

A search system comprising:

• (A) a central server having an index, wherein said index is also available on at least one computing device in a distributed computing network, said at least one computing device being distinct from said central server, each said at least one computing device having a cache in which said computing device stores data generated during the course of said computing device's access to another computing network distinct from said distributed computing network;
• (B) computer program code stored in a memory of at least one of said plurality of computing devices for
• (B)(i) automatically and periodically generating said index based on data in said cache folder, and
• (B)(ii) automatically and periodically transmitting said index to said central server;
• (C) a first client connected to said distributed computing network, said first client having access to a copy of said index;
• and
• (D) a second client connected to said distributed computing network, wherein said first client receives a search request from said second client, and, in response to said search request, fulfills said request by searching said copy of said index,
• wherein said first client has a distributed search engine application for receiving and fulfilling search requests from said second client, and
• wherein said distributed search engine application transmits an invoice with the search response to said requesting search client application, and
• wherein the search client application, upon receiving the search response, digitally authenticates the invoice and returns an authenticated receipt to said distributed search engine application, and
• wherein said distributed search engine application collects authenticated receipts and periodically transmits at least a portion of said receipts to the central server.

A method, in distributed search system comprising:

• (a) a central server having an index, said index also being available on a computing device in a distributed computing network, said computing device being distinct from said central server, said computing device having a cache in which said computing device automatically stores data generated during the course of said computing device's access to another computing network distinct from said distributed computing network;
• and
• (b) computer program code stored in a memory of said computing device for automatically and periodically generating said index based on data in said cache folder, and for automatically and periodically transmitting said index of said data to said central server;
• (c) a first client connected to said distributed computing network, said first client having access to a copy of said index;
• and
• (d) a second client connected to said distributed computing network, wherein said first client receives at least one search request from said second client, and fulfills said request by searching said copy of said index,
• wherein said first client has a distributed search engine application for receiving and fulfilling search requests from said second client,
• the method comprising:
• (A) said distributed search engine application transmitting an invoice with the search response to said requesting search client application, wherein the search client application, upon receiving the search response, digitally authenticates the invoice and returns an authenticated receipt to said distributed search engine application, and
• (B) said distributed search engine application collecting authenticated receipts and periodically transmitting at least a portion of said receipts to the central server.