Sanitize 1.1.0 is now available. The biggest change in this release is a migration from Hpricot to Nokogiri, contributed by Adam Hooper. In addition, a new :output config setting allows you to specify whether you want Sanitize to output XHTML (the default) or HTML4, and Peter Cooper contributed a fix for a bug in which Sanitize would incorrectly strip a whitelisted URL if a path segment contained a colon.
To install or upgrade Sanitize via RubyGems, run:
gem install sanitize