I accidentaly selected one of my co-workers caledars and synced with it. Now it appears in my calendars list on the iPhone, and I don't know how to delete it. Simply unchecking it in iTunes doesn't help (I've actually disabled the sync of celndars in iTunes as I want to only sync OTA).
ssh into your ipod then go to
/private/var/mobile/Library/Calendar
and just in case.. copy the file Calendar.sqlitedb to your computer
it should be fine i did it myself (FW 2.1)
then delete it
open up calendar and it should be empty