I wrote a daemon that logs the results of SHOW GLOBAL STATUS and SHOW MUTEX STATUS every x seconds to graphite or a CSV. You may find it useful: https://github.com/9minutesnooze/mysampler. It can provide you insight into all the MySQL status information at whatever granularity you choose. There isn't any documentation yet, but I have found the output highly useful, either by pulling the CSV into gnuplot or (better) viewing the results in graphite to correlate with other metrics. I plan on extending it soon to parse SHOW ENGINE INNODB STATUS as well. I'm sure there is other data from INFORMATION_SCHEMA that would be valuable to add in, but I haven't gotten there yet.
For slightly less granular and more processed results, the Percona Cacti Templates are very good, but only show problems that have existed for a "long" time. They do show some interesting trending information and, as with most charts and graphs, the differences over time are what tend to be most enlightening.