This is a good and easy way to get wins in Alterac Valley or just pwn some horde.
What you do is Create or join a raid of 40 people or the ammount you want, (whatever, your choice) and make yourself the leader or have the raid leader talk to the Alterac Vcalley battlemaster and with the chat window The LEader of the raid types /script JoinBattlefield(0,1); into the Chat window.
The whole raid should then be queued at the same time and hopefully most of the raid members will get into the same AV. The others who were unlucky, and didnt make it in just queue up to whatever number AV the majority of the members got in.
A tip to get people out is to have a mage open a port to OG and tell people to help summon, the people will click the portal, and then leave the BG, thus allowing your raid members to join.