I was wondering if it'd be possible to monitor a Ventrilo server via PHP to display "Online" and "Offline" on a webpage for each situation, nothing more just plain text . Any help would be much appreciated!
Short answer: yes.
Open a port using fsockopen to the ventrilo server, and if it replies without timing out then presumably its online (or something else is on that port). If you can get ahold of the technical specs for the communication, you can actually prompt it to "talk" with you to verify that it is the application expected.