how about a friends list:
add all your freidns
then you can pm them all at the same time to tell them about and upcoming event

how about more than 6 people per pm?
its hard todo just 6 at a time

how about a RC car game on this site
with racing and prizes

we do the 6 PM limit to avoid abuse. some people might come to rcu to spam our members. this limit slows them down enough so we can catch them and ban them before they bombard 100,000 plus users with PM's. It acts as a governor of sorts.

you can add all your friends to your list on the PM page and see when they are online. just add them to your address book.

also you can create an event using our calendar http://www.rcuniverse.com/forum/calendar.asp

you can enable the event so users can signup to it and even enable discussions on it. this might do what you want.