Chat with more than one buddie

[vmaster.mail at gmail.com]

I love Pidgin chat, bit I can't figure out this simple thing which seems 
intuitive in other messengers.

If I'm talking to a buddy say on Yahoo or MSN and want to add another 
buddy into the conversation how do I do this?
I can get invited into chats with other people, it opens a room, but how 
do i initiate one myself? I can 'invit someone 2 chat
but no obvious way to invite anyone else in?

Mike