+1, I have setup an instance last week for friends and family and I have to say I am excited how good it works. Can even be hooked up to a SIP PBX so people from ordinary phones can join in.
In my case I used a VPS with 2 CPUs and 2GB RAM running Debian, tested it with 5-6 participants.
Had the first "virtual" dinner with parents yesterday and while strange it gave some feeling of normality.