Ive been using GSC for a while and its a voice/text chat kinda like vent, and the servers are free.
Ive started a free 200ppl server if anyone would like to join.
Go to
http://www.getgsc.com and download the client and register.
Start the thing up, let it update.
When it opens, click on te "Voice" tab and click "Add".
Search for SRF and add it.
ENTER!