You can go on the Ventrilo that Rathamus set up.
That's premades, generally for horde, mostly AV but some IoC and around 95% horde wins.
Take a look at oQueue as well (same author as Keyclone), for premades.

Without follow in battlegrounds, you have your work arounds.
A multi-person mount, and then IWT to whatever you want to kill with melee toons.
Or you can have a Druid on your team, who uses the Stag glyph when they go into travel form, which your other toons can IWT to attempt to mount them.
I didn't like the work arounds, but they're worth trying if you want to participate in battleground PvP.