Quick notes for installing libmemcached and Evan Weaver’s memcached gem, in case I forget (again):

1. Get libmemcached source from http://tangent.org/552/libmemcached.html. Configure, make, make install. Make sure you get a version compatible with the Ruby memcached gem by opening the COMPATIBILITY file in the memcached gem files.
2. gem install memcached
3. Create a symlink ln -s /usr/local/lib/libmemcached.so.2 /usr/lib/.
4. Try it out with irb -rubygems, require 'memcached'