I had done some reading on Followers at this website: http://www.uesp.net/wiki/Skyrim:Followers and learnt that its possible to have that many following me??? WOW!!! Can i build an army!?! because firstly, yea...i have permanent followers and there are Quests Followers who will only follow me until the quests are done. BUT what if i do not complete those quests? (O.O)....
i mean...well...let's just count the "living things" that follow me:

PERMANENT
[1] i have my own dog [eg - Vigilance]
[2] i have my own permanent follower [eg - Lydia]

TEMPORARY
[3] Barbas [a dog] - Quest: A Daedra's Best Friend. Won't die
[4] Esbern [a conjurer class] - Quest: A Cornered Rat. Won't die
[5] Avulstein Grey-Mane [a warrior class] - Quest: Missing in Action. Won't die
[6] Thonnir [a lumberjack] - Quest: Laid to Rest. Won't die

woh!!! that's 7 [including myself] in a party! PARTY!!!

(!_!)...i see its possible to get MORE!!!

[7] Thorald Grey-Mane [a blacksmith] - Quest: Missing in Action. If he dies, you will fail the quest. Avulstein Grey-Mane, Geirlund, and Vidrald will also stop following you.
[8] Geirlund [a warrior class] - Quest: Missing in Action
[9] Vidrald [a warrior class] - Quest: Missing in Action

ALL IN ALL --- 10!!! DRAGON RAID!!!


NOT FORGETTING...
[10-11] Atronach, which is possible to summon 2 if one max out Conjuration Class.

oh wait...theres one more...
[*] horse.
so its 13. well...the horse doesn't follow. but if it does happen to be nearby, it does help to attack sometimes and also draws enemy's attention.

AWESOME!!! Are there anymore Quests that NPCs will follow?

What about Dead Thrall? Sure, it's not a living thing, but permanent.

Damn, you could have your own little army

There are also 3 relatively powerful summonable shades - one is a reference to Oblivion, one is a reference to morrowind sort-of and a powerful mage, and the other is acquired in the end game. You can only have one of those summons out at at time though and they are temporary - but they are all fairly powerful.

Be careful - some quest followers will dismiss your other followers. Also, if you're on the pc you can always use:

set playerfollowers to 0
set playeranimals to 0

Do that every time you buy a dog or recruit a follower and it thinks the slot is open. This will, of course, break the game badly and cause all manner of glitches.

I did try to have Lydia and Aela the huntress (during a quest) and Lydia just stopped following me and I found her back at my house. So I think there's a limit to one at a time.. Could be wrong though.

i had two (lydia + 1) when i did the college initiation, however when i did the companions initiation lydia took off. side note: i had 3 horses and a dozen Dawnstar villagers help me with a blood dragon. it didnt last very long though.

http://youtu.be/dBebnsGZL3s

AWESOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOMMMMMMMMEEEE...

TIME TO GATHERRRR!!!!!!!!!!!!!!!!!!
DOVAHKIIN'S ARMY RAIDS SKYRIM!!!

Thonnir (Laid to Rest) - how do I get rid of him? He's annoying, always getting in the way - when we're outside Movarth's Lair and I tell him I don't want his help he ignores me and comes anyway.
He won't start to sneak when I do . . . . I've tried losing him but he's very persistent! Thanks!

I have the guy who I am supposed to kill for the cannibal quest. I have him follow me, but when I got to barbas Barbas isnt around. So I think youre only allowed one quest follower at a time. So I imagine you can have a horse, a dog, a shield guard and one temporary immortal quest follower, and a conjured of some kind. I dont think you can get more than that. At least not beyond whatever quest the last tempporary follower you have is on. So if I went right ot the quest where barbas was going (since he was the second quest follower I talked to) then he will follow me there, but I dont think he will follow me anywhere else. At least he didt when I fast traveled some where.

Legion. :3

change those 2 artonach to 2 dead thralls. Use it on 2 summoning mages and you got 2 mages + 2 summons. Four >> Two

it seems to be kind of random
sometimes your follower leaves
but if you like pick up an npc mid qeust (saving some1 for instance) you have 2 followers
got me thinking how many could I have
but I never bothered trying because one seems more than enough

ow there's also this quest where you have to free that grey mane (or battle born always forget) from prison and you get 3 followers at once
dno if you can keep them by just skipping the quest but if you could it would really add up fast