Tricks and Treats of Azeroth

Ironically, Outland is not in Azeroth, even though it is required for the achievement...

As a mage with all flightpaths (or if you're doing the quests with a mage friend), I found it easiest to get them in the following order. Teleporting as often as possible to save time.

(F) = Fly
(T) = Teleport / Portal
(W) = Walk

Kalimdor:

1. 
   
2. Orgrimmar (Start here)
3. 
   
4. Winterspring, Everlook (F)
5. 
   
6. Orgrimmar (T)
7. 
   
8. Ashenvale, Splintertree Post (F)
9. 
   
10. Thunderbluff (T)
11. 
    
12. Stonetalon, Sun Rock Retreat (F)
13. 
    
14. Desolace, Shadowprey Village (F)
15. 
    
16. Feralas, Camp Mojache (F)
17. 
    
18. Silithus, Cenarion Hold (F)
19. 
    
20. Tanaris, Gadgetzan (F)
21. 
    
22. Thousand Needles, Freewind Post (F)
23. 
    
24. Dustwallow, Mudsprocket (F)
25. 
    
26. Dustwallow, Brackenwall (F)
27. 
    
28. Barrens, Camp Taurajo (F)
29. 
    
30. Barrens, Crossroads (F)
31. 
    
32. Barrens, Ratchet (F)
33. 
    
34. Thunderbluff (T)
35. 
    
36. Mulgore, Bloodhoof Village (W)(Or slowfall and jump off the cliff)
37. 
    
38. Orgrimmar (T)
39. 
    
40. Durotar, Razor Hill (W)
41. 
    

Eastern Kingdom:

1. 
   
2. Swamp of Sorrows, Stonard (T)
3. 
   
4. Stranglethorn, Grom'gol (F)
5. 
   
6. Stranglethorn, Booty Bay (F)
7. 
   
8. Swamp of Sorrows, Stonard (T)
9. 
   
10. Badlands, Khadgar (F)
11. 
    
12. Arathi Highlands, Hammerfall (F)
13. 
    
14. Hinterlands, Revantusk Village (F)
15. 
    
16. Hillsbrad Foothills, Tarren Mill (F)
17. 
    
18. Silverpine Forest, The Sepulcher (F)
19. 
    
20. Undercity (T)(Or fly if you're cheap)
21. 
    
22. Tirisfal Glades, Brill (W)
23. 
    
24. Silvermoon (T)(Or get the orb if you're cheap)
25. 
    
26. Silvermoon, The Royal Exchange (W)
27. 
    
28. Silvermoon, The Bazaar (W)
29. 
    
30. Eversong Woods, Falconwing Square (W)
31. 
    
32. Eversong Woods, Fairbreeze Village (W)
33. 
    
34. Ghostlands, Tranquillien (W)(Or walk to Silvermoon and Fly from there)
35. 
    
36. Eastern Plaguelands, Light's Hope Chapel (F)
37. 
    

Outlands:

1. 
   
2. Shattrath (T)
3. 
   
4. Nagrand, Garadar (F)
5. 
   
6. Zangarmarsh, Zabra'jin (F)
7. 
   
8. Blade's Edge, Thunderlord Stronghold (F)
9. 
   
10. Blade's Edge, Mok'Nathal Village (F)
11. 
    
12. Blade's Edge, Evergrove (F)
13. 
    
14. Netherstorm, Area 52 (F)
15. 
    
16. Netherstorm, The Stormspire (F)
17. 
    
18. Shattrath (T)
19. 
    
20. Zangarmarsh, Cenarion Refuge (W)(Or fly to Swamprat and walk from there)
21. 
    
22. Shattrath (T)
23. 
    
24. Terokkar Forest, Stonebreaker Hold (F)
25. 
    
26. Shadowmoon Valley, Shadowmoon Village (F)
27. 
    
28. Shadowmoon Valley, Aldor/Scryer Inn (F)
29. 
    
30. Shattrath (T)
31. 
    
32. Hellfire Peninsula, Falcon Watch (F)
33. 
    
34. Hellfire Peninsula, Thrallmar (F)
35. 
    

With your home location in a good place, you might be able to change the order a bit.
For example, I had my home location in the scyer inn in shadowmoon valley so I did that part in reverse (going to shatt instead of from shatt). All of them can probably be taken in under 2 hours.

Note: If you're doing all of these the same day, I recommend doing an AV afterwards to get the G.N.E.R.D Rage achievment. The candy disappears in 24 hours so you gotta do it fast!

I took your advice and spent some time today to make a list. These are the horde innkeepers using wowhead as a way to locate them. This is made for the tomtom mod, and coordinates are separated into macro blocks. These are innkeeper coordinates only. Some inns may not have what you need.

/way Arathi Highlands 69.0, 33.2
/way Ashenvale 12.8, 34.0
/way Ashenvale 74.0, 60.6
/way Ashenvale 50.4, 67.0
/way Ashenvale 38.6, 42.2
/way Azshara 57.0, 50.4
/way Azshara 57.0, 50.2
/way Badlands 18.2, 42.8

/way Blade's Edge Mountains 53.2, 55.4
/way Blade's Edge Mountains 76.0, 60.2
/way Blasted Lands 40.4, 11.6
/way Borean Tundra 49.6, 10.0
/way Borean Tundra 76.2, 37.2
/way Borean Tundra 41.8, 54.6
/way Dalaran 65.6, 32.6

/way Desolace 24.0, 68.2
/way Dragonblight 38.2, 46.0
/way Dragonblight 76.8, 63.0
/way Durotar 51.6, 41.6
/way Dustwallow Marsh 36.8, 32.2
/way Eversong Woods 48.0, 47.6
/way Eversong Woods 43.6, 71.2
/way Feralas 74.8, 45.0

/way Feralas 41.4, 15.6
/way Feralas 51.8, 47.6
/way Ghostlands 48.8, 32.4
/way Grizzly Hills 65.4, 47.0
/way Grizzly Hills 20.8, 64.6
/way Hellfire Peninsula 26.8, 59.6
/way Hellfire Peninsula 56.6, 37.6

/way Hillsbrad Foothills 60.2, 63.8
/way Hillsbrad Foothills 35.8, 61.2
/way Hillsbrad Foothills 57.8, 47.2
/way Howling Fjord 52.2, 66.4
/way Howling Fjord 49.4, 10.8
/way Howling Fjord 79.6, 30.8
/way Icecrown 76.0, 24.0

/way Mulgore 46.8, 60.4
/way Nagrand 56.6, 34.6
/way Northern Barrens 62.4, 16.6
/way Northern Barrens 49.6, 58.0
/way Northern Barrens 56.2, 40.0
/way Northern Stranglethorn 37.2, 51.8
/way Orgrimmar 32.8, 65.6

/way Orgrimmar 39.8, 81.8
/way Orgrimmar 53.6, 78.8
/way Orgrimmar 39.2, 48.4
/way Orgrimmar 70.6, 49.2
/way Shadowmoon Valley 30.2, 27.8
/way Silvermoon City 79.6, 58.6
/way Silvermoon City 67.8, 72.4

/way Silverpine Forest 44.4, 20.6
/way Silverpine Forest 46.4, 42.6
/way Southern Barrens 39.2, 20.0
/way Southern Barrens 40.8, 69.2
/way Stonetalon Mountains 50.4, 63.8
/way Stonetalon Mountains 66.4, 64.2

/way Swamp of Sorrows 46.8, 56.8
/way Terokkar Forest 48.8, 45.0
/way The Cape of Stranglethorn 35.0, 27.2
/way The Hinterlands 78.2, 81.2
/way The Hinterlands 31.8, 58.0
/way The Lost Isles 39.6, 27.8
/way The Lost Isles 42.6, 16.2

/way The Lost Isles 36.0, 67.4
/way The Lost Isles 28.0, 75.8
/way The Lost Isles 45.0, 65.4
/way The Storm Peaks 67.6, 50.6
/way The Storm Peaks 37.0, 49.6
/way Thunder Bluff 45.8, 64.6
/way Tirisfal Glades 60.8, 51.6

/way Tirisfal Glades 83.0, 71.8
/way Twilight Highlands 75.8, 52.6
/way Undercity 67.8, 38.6
/way Western Plaguelands 48.2, 63.8
/way Zangarmarsh 30.6, 50.8

The ones below are neutral locations:

/way Badlands 65.8, 35.6
/way Blade's Edge Mountains 62.8, 38.2
/way Borean Tundra 78.4, 49.2
/way Dalaran 37.0, 56.8
/way Dalaran 51.0, 40.0
/way Deepholm 49.8, 52.0
/way Desolace 56.8, 50.0

/way Dragonblight 48.2, 74.6
/way Dragonblight 59.8, 54.2
/way Dustwallow Marsh 41.8, 74.0
/way Eastern Plaguelands 75.6, 52.4
/way Felwood 44.0, 61.8
/way Felwood 44.8, 29.0
/way Howling Fjord 25.4, 59.8

/way Isle of Quel'Danas 51.2, 33.4
/way Mount Hyjal 63.0, 24.0
/way Netherstorm 43.4, 36.0
/way Netherstorm 32.0, 64.4
/way Searing Gorge 39.6, 66.0
/way Shadowmoon Valley 61.0, 28.2

/way Shadowmoon Valley 56.2, 59.8
/way Shattrath City 56.2, 81.6
/way Shattrath City 28.2, 48.4
/way Shimmering Expanse 49.2, 42.0
/way Sholazar Basin 26.8, 59.2
/way Silithus 55.4, 36.6
/way Swamp of Sorrows 71.6, 13.8

/way Tanaris 55.6, 60.8
/way Tanaris 52.6, 27.0
/way The Cape of Stranglethorn 40.8, 73.8
/way The Storm Peaks 48.8, 65.0
/way The Storm Peaks 30.8, 37.4
/way The Storm Peaks 41.0, 85.8
/way Thousand Needles 76.6, 74.8

/way Uldum 54.6, 32.8
/way Un'Goro Crater 55.2, 62.2
/way Winterspring 59.8, 51.2
/way Zangarmarsh 78.6, 63.0
/way Zul'Drak 40.8, 66.2
/way Zul'Drak 59.2, 57.2

I have the alliance locations as well in tomtom format. I just haven't separated them into macro blocks. Post if you need a copy. I also have it saved in xls format.