ACM members meet between meetings through several informal and shared discussion channels. Visitors are always welcome to join into these discussions. Please note that none of these discussion channels are "official" or ACM sponsored.
Many of RPI's ACM members meet on the OFTC IRC network, in #rpi. Either point your favorite irc client to irc.oftc.net, or join in via the web at http://poundrpi.net/~webirc/
Lily is a CMC system developed at RPI. Similar to IRC, users meet in discussion channels formed around various topics or interests. However, Lily has quite a few extra features beyond what an IRC server provides, including stored/offline messaging, the ability to review discussions, a broadcast feature allowing users to communicate with multiple discussions at once, and access controls requiring a vaild username and password for each participant. Visit http://rpi.lily.org:7780/new/ to sign up for a lily account.
usenet.rpi.edu carries a number of RPI specific discussion groups, including the popular rpi.general, and rpi.acm. You must be within RPI's firewall, or on one of the RPI, ACM, or CS Department remote access machines to use usenet