Global Climate Data distributes tools written in MATLAB for creating historical monthly precipitation and mean temperature data downscaled to 30 arc-seconds.  The process utilizes globally available gridded data, allowing users to produce high-resolution monthly surfaces for any land surface on the globe.  All of the tools are open source and available on this site free of charge.
Recent updates to the website include the downscaling package and an associated user manual.  Please do not hesitate to contact Thomas Mosier (mosiert@onid.orst.edu) with questions on how to use these tools, comments on this work, or suggestions.