I know there are a lot of people out there who like to level (atleast to some extent) by doing the pet battle dailies. These dailies are always a part of my daily routine for the character I am focusing on. The character I hace been leveling the most lately is my little druid. She have been doing the Easter Kingdom Fights and the master in Winterspring for a while now. When she dinged 58 and got out to Outland the first thing she did was the pet battle dailies out there (as a druid she can fly in Outland at lvl 58).
When she dinged 60 and got the ability to fly in Kalimdor and Eastern Kingdoms I decided to try some of the cataclysm trainers. You can get to three of the four trainers by flying (you can’t go down to Deepholm for the fourth). The one out in Hyjal comes with the risk of bodily harm from the mobs around him, but if you are careful and time it right you can manage. This is three additional quests for her to do each day, and one of them gives a Sack of Pet Supplies. The cata quests don’t give much more exp than the previous ones, but the daily battles give a lot of exp to start with. So having three more makes a difference.