memcached-pro is a improved version of memcached for adding many new useful command,such as "cget","cappend" and "cprepend"...
cget-allow you get a key-value then clear value(not delete) in a atomic operation.
cappend-allow you append a value to a key, then cut the value to the max length you set in command in a atomic operation.
cprepend-allow you prepend a value to a key, then cut the value to the max length you set in command in a atomic operation.
There are about twenty new command in memcached-pro right now. Perhaps,they are helpful to your project.
The package for download will be comming soon:)