Saw a thread about how you can Invite people to your group if you are not leader. Well i got to messing around with it and i also found out that you can Uninvited People in the same way.
All you have to do is. If you where once the party leader you can type
"/kick Player Name"
This is Great when you are In the LFG system and you happen to be the first person in the group and the LFG system changes party leaders. And just happen to run into someone you don't like! Make them think that the leader kicked them =P
Note: Ya cant Kick The Real Party leader with this.