I've been quietly working on Typhoeus for the last few months. With the help of Wilson Bilkovich and David Balatero I've finished what I think is a significant improvement to the library. The new interface removes all the magic and opts instead for clarity.
It's really slick and includes improved stubing support, caching, memoization, and (of course) parallelism. The Typhoeus readme highlights all of the awesomeness. It should be noted that the old interface of including Typhoeus into classes and defining remote methods has been deprecated. I'll be removing that sometime in the next six months.
In addition to thanking everyone using the library and everyone contributing, I should also thank my employer kgbweb. If you're a solid Rubyist that likes parsing, crawling, and stuff, or a machine learning guy, or a Solr/Lucene/indexing bad ass, let me know. We need you and we're doing some crazy awesome stuff.