How do you know if memcached is doing anything?

You could use the official perl script:

memcached-tool 127.0.0.1:11211 stats 

Or just use telnet and the stats command e.g.:

# telnet localhost [memcacheport]
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
stats
STAT pid 2239
STAT uptime 10228704
STAT time 1236714928
STAT version 1.2.3
STAT pointer_size 32
STAT rusage_user 2781.185813
STAT rusage_system 2187.764726
STAT curr_items 598669
STAT total_items 31363235
STAT bytes 37540884
STAT curr_connections 131
STAT total_connections 8666
STAT connection_structures 267
STAT cmd_get 27
STAT cmd_set 30694598
STAT get_hits 16
STAT get_misses 11
STAT evictions 0
STAT bytes_read 2346004016
STAT bytes_written 388732988
STAT limit_maxbytes 268435456
STAT threads 4
END

I know this question is old, but here is another useful approach for testing memcached with django:

As @Jacob mentioned, you can start memcached in very verbose mode (not as a daemon):

memcached -vv

To test your django cache config, you can use the low-level cache api.

1. First, start up the python interpreter and load your django project settings:

   python manage.py shell
   

2. From the shell, you can use the low-level cache api to test your memcache server:

   from django.core.cache import cache
   cache.set('test', 'test value')
   

If your cache configuration is correct, you should see output in memcache similar to this:

<32 set :1:test 0 300 10
>32 STORED