External search utilities can often be more efficient than the internal one, and does save some memory and network resources for you.
That list is far from being exhaustive. Many search, indexes and forum sites exist, in lots of languages (english, german, french, spanish, russian, japanese...), and some are even specialized (anime, ebooks...)
For instant results. Not too deep though.
Old one. Seems to work every now and then.
Created after the demise of ShareReactor, both to report what's happening to its owener and to list alternative billboarding sites and sites that archives of all but the last few SR releases.
Java utility to search the donkey-network without a donkey-client
There are also other miscellaneous utilities for the ultimate donkey experience.