If you are looking for a nice solution to create specific stats on your podcasts, check out podalyzer: hexten dot net slash podalyzer
You will need a fairly up to date setup of Perl to utilize podalyzer. I ran some tests and found it is excellent for making stats from your mp3s.
I did have a problem trying to use stats from libsyn. Libsyn is doing some funky stuff with the logs, instead of 200 ok status messages there are 202 status messages and the path saved in the log is not the same path that is in the URL. Hopefully a future version of podalyzer will be able to handle this pitfall.