I did the same thing with my troll. I had a Ghost Saber until 57 (at which point I tamed the constantly-yawning Rakshiri that drove me nuts all the way up to 70 raids).
I'd had enough of that cat and ditched it for another Ghost Saber... Luckily, I had a few close friends in my guild that offered to help me with the grind now and then.
If you're geared well enough (or the proper spec), just take your pet into instances. Be SURE to make certain that your party doesn't mind you having an underleveled pet. Because of my gear, I'm able to get away with being BM and leveling up lowbie pets in pick-up instances (still top DPS in most cases XD). Exp goes by really fast that way, and it's not nearly as dull.
If you grind with a guildie, be aware that your pet also receives the exp decrease for being grouped.
If you don't have the luxury of having cool guildies (or being epixed for instancing with a lowbie pet), I found that the Ogres at Laughing Skull in Nagrand are really easy to grind. For some reason they seem to have lower HP than most mobs in that zone, and you can work on getting rep for two factions at the same time (Consort/Faction Base as well as Powder for Halaa).