I rewrote an existing ruby client "hbase-ruby" to work with the Stargate interface, and released it on Github/Gemcutter. Stargate seems to be working great and the ruby client supports all the existing features (including scanners!) while maintaining the API for anyone that was using a previous version of hbase-ruby. If I release more versions, I think I'll be modifying the API though.
Github: http://github.com/greglu/hbase-ruby Gemcutter: http://gemcutter.org/gems/hbase-ruby -Courtesy of Openplaces
