What we need is quite simply a very good protocol for distributed search. It takes some storage, some bandwidth and some cpu cycles. Have people contribute those and earn queries and indexing. Make it very good but simple enough for a half decent programmer to make a lvl 1 node that can only announce it exists. Trackers, supper nodes, ban lists, ranking algo's etc etc Write server code in all the languages, have phone and desktop clients. There can be subscription based clients too so that the cpu, storage, bandwidth can be done for you by a company.

This description is intentionally vague.