This time, I'm creating a VOIP application for Minecraft! It will include a plugin for bukkit users, and a server mod for non-bukkit users. Currently, I'm doing research on SIP and VOIP, and should be ready to code as soon as sun.java comes back up. (http://www.oracle.co...ance/index.html). My end goal is to have a mod that can detect which user(s) have installed the mod, and which users have not installed it, and can call any at will, as well as add users to their "contact" list.
Anyway, if you have any experience with SIP, please contact me, as the more I get contacted, the faster this will be completed!