Krugal seems to be a nice project for searching code snips and algorithm implementations.  Currently mostly sourceforge stuff, I found some very familiar code ;-)  also alternate implementations I’d like to look at in detail

Krugle is designed to locate code. Krugle supports code search by crawling, parsing and indexing code found in all open source repositories, as well as code that exists in archives, mailing lists, blogs, and web pages. (http://corp.krugle.com/product/index.html)

Definitly still in beta, but seems to work pretty well.