Sporeggar, Lagoon's char, used to boost us all to Exalted with Sporeggar. It took him about 8 hours to get us there, just running circles round and round and round in the cave on a DK. He did it for 5 of his chars, about 20 others on AP got the tabard because of his help.
Actually I did 9 F2p chars of mine, one of each class, didnt quit, just one day logged into my very first server and decided to finish all professions on 39,49 tinks (it was around the time when there was skinning/herbing glitch so you can go 1-525 on lvl 5 mobs). After I was done with that I updated my 85's to free LFR gear and then reconnected with old friends and decided to finally finish 70 and 80 tinks. Now that's about to be done so I just need to get myself to log onto Sporeggar DK again. If i remember correctly i still need 1 more magician's mantle anyway but i know once i log back, i will get some crazy idea like finishing diplomat on all 9 toons and i'm kinda scared of that. But i'll be back one day. ATM just logging for free LFR and sunwell and occasionaly playing 80 bracket, which is suffering from x4's problem as well, mainly rogues, and blood DK's, but i guess that's how it will be everywhere, makes victory that much sweeter though. And i had to reregister, forgot lagoons info on TI and email was deactivated cause of long time innactivity. Anyway i'll see you soon guys
Lagoon
Btw, on lvl 70 DK (stayed at 70 due to getting tazik first time), it takes 8 hours to go from unfriendly to exalted, but you can't have more than 4 people with you in group, after that there's 20 percent rep gain penalty for each member above that (meaning raid of 10 ppl get's 0 rep)
The cave is best because it gives rep all the way to exalted and f2p toon can sit there alive on the ledge inside and still be in range for all rep kills (actually you need to pull 3 mobs outside closer to cave but it's easy with taunting one, rocket other and DG 3rd.
There is way to glitch like 50 mobs together cause of low lvl sitting on top of shroom (some epic times there) however it is not advisable as people may report you, and it's not worth it.
At 70 with tazik you pretty much just run from one to other nonstop (DC, 1 white shot, or DS and if there are no questing folks, as soon as you kill all, first respawn within 15-20 sec. Good luck
EDIT: That picture with achivement, that's the spot you have to pull 3 giants to so that f2p's on ledge inside get rep for them