I installed memcached on Ubuntu box. Installed MongoDB too on the same machine to compare the performance for these two.
Storing in MongoDB 0.0940001010895 for 220 records Storing in memcached 83.2030000687 Reading from MongoDB 0.0309998989105 Reading from memcached 85.3599998951 All time in seconds. I'm using python libray http://www.tummy.com/Community/software/python-memcached/
