I have two recommendations.
Insulation on the exterior of the foundation is the best method. If you can install it on the exterior install a minimum of R-10. Also make sure that the insullation is treated for ground contact.
Install a dehumidifier to remove moisture from the air in the basement or crawlspace. This will eliminate the moisture in the air that is condensing on the block walls which are colder.
For more information:
Read "How can I install insulation in my downstairs, built with cinder blocks?" a Q&A answered by Harold Remlinger.