Nagios plugins written by me for work.
This plugin will monitor the number of calls, channels, SIP peers & IAX2 peers
This plugin will tell you toner/drum levels for printers over SNMP, currently it's assumed anything that isn't a Cannon or a HP are in CMYK (Cannon/HP seem to be in KCMY).
More plugins will appear as I write them, and some can't be made public due to the devices they talk to.