Level 1-60 in 7 hours

From http://www.dual-boxing.com/forums/index.php?page=Thread&threadID=23107&s=10b799aa3877d373e2c96bafaabce1e70ca71e4f

7 hours and about 12 minutes is my fastest RAF boost time from 1-60, but that included a Warlock summon chain so that it was pure instancing the whole way with no training or running around. That includes the 1-10 by hand, which takes an hour or so. I could probably shave a half hour off of that time if I ran my DK and had someone else MB the alts so I didn't have to worry about them.

1-10 Hand Grind
10-15 Wailing Caverns
15-20 RFK
20-35 SM Cath + Armory
35-45 ZF
45-55 LBRS
55-60 Ramparts

Questing and WC are self explanatory. RFK you can go straight to the last boss, drop off the ledge behind her, and then kill boars all the way to the zone and reset. With my DK I can clear all of Cath and Armory in about 8 minutes, so I usually take a break for a few minutes so I don't cap the instance per hour. For ZF also you can make a huge circle and kill mobs the whole way. LBRS I zone in and move down to the first area where you see the ogres on your right. I jump down to the lava area and then clear up back to the entrance from there. Ramparts is the same where you can do the whole zone in under 10 minutes, including bosses.

I don't even get the chance to use Pestilence to spread diseases until I hit LBRS. The key is keeping up Unholy Blight so you tag each mob and the pet will do a lot of the work. Once you hit LBRS you can round up a bunch and give them one disease, then hit a fresh mob and spread the other one. One disease is enough to kill any of the mobs there, but it does go faster if you can get both going.

More information ....

Use RAF efficiently
http://wow-exploits.blogspot.com/2008/09/world-of-warcraft-recruit-friend.html

More Power Leveling
http://www.dual-boxing.com/forums/index.php?page=Thread&threadID=3948&pageNo=1&s=a178843cc55961362c0cff4873f5d80775cd1395