Edit--Ooops, sorry, forgot this was a power-leveling guide for dual-boxers when I first posted this. Hmmmm. In that case you will need help from a high level friend who has a warlock if you are dual playing a couple of lowbies.

Warlocks can be taken up a notch or two as high-level helpers under these conditions:

1) You have at least 2 lowbies grouped together in a party.

2) You have 1 or more high-level warlocks, preferably with Felguard pets, NOT grouped with the lowbies.

3) You tag a mob with the lowbie.

4) You kill the mob with JUST the Warlock pet(s) -- don't use any damaging warlock spells.

5) You get FULL XP for the kill -- split between your lowbies of course.

I'm currently doing this with two 60 level warlocks helping 2 mages who have just reached 30.

At some point as I level I'm sure it will take too long for the pets to finish off the mobs without some additional aid from the mages. That's fine as I'll start using the pets mostly as tanks for the mages. When I get about 10 or so levels away from the warlocks, the mages can then start tagging mobs and then I can use the full power of the warlocks to make kills and get full XP (as long as the mob is not grey to the warlocks).

I guess this works for high level hunter pets too, but I don't have any to try it with.