A while back I created the Why Ruby repository on RubyForge as a place to collect Ruby Presentations that are freely available to those who are trying to answer the question "Why Ruby?" to their colleagues and associates.
Jim Weirich just contributed his excellent presentation of OSCON 2005 titled "10 Things Every Java Programmer Should Know About Ruby". You can download it from here:
http://rubyforge.org/docman/?group_id=251
and the home page for Why Ruby is:
Curt