I'm at a whopping 3 days 16 hours.

That's whopping. 
 
I got to 2 days 10 hours something and then I got bored.

4 days 9 hours : /

2 days 1 hour, Multiplayer 
18 hours, Spec Ops 
1 day, Single player

" wow.. you guys play wayyy too much, i'm just pushing 1 day overall "

I'm on 3 days something - not entirely sure. I do know someone though that has played it for like 15 days.

" 4 days 9 hours : / "

4 days and 12 hours........... 
To be fair to myself some of that is from leaving it on for six hours whilst doing something else

Giant bomb user Druminator has played it for 6 days and 13 hours, that might just be multiplayer aswell

2 days something then stopped playing to pursue other online adventures:

• Uncharted 2
• Killzone 2
• Battlefield 1943 (Half Price) :D

5D19H, multiplayer only.

5 days, ?? hours

5 days, 00 hours, 34 minutes. Level 17 on 2nd Prestige.

8d 04h 32m second prestige level 46

Little over a day.

Like, 6 days or something around there. I'm bored with the game now, having beat the single player campaign twice and prestiged.

I clocked in about 5 days worth of playtime; prestiged once online.

800000000000000000000000000000000000000000000000000000000000000000000 nano seconds :)

" 800000000000000000000000000000000000000000000000000000000000000000000 nano seconds :) "

4 days, 18 hours, 47 hours, 24 second (3 days, 23 hours, 17 minutes, 20 seconds for mutiplayer). Good value for a $60 FPS.

I'm spent about 8 days and 9 hours into the multiplayer so far. Probably another 4-6 hours today.  EDIT: 8 days and 9 hours = 201 hours.
 
Around 29 hours in Spec Ops and 18 hours into the campaign.
 
Also, if you want to correct multiplayer time, you have to go to the Barracks, that gives you your actual in game play time. The stats page gives time spent in menus. That counts for all three sections.
 
So you could probably take away an hour or so from my Spec Ops and an hour from my Campaign time...

I'm at 2 days 18 hours IIRC

1 day 11 hours.

2 days 5 hours

" 4 days and 12 hours........... To be fair to myself some of that is from leaving it on for six hours whilst doing something else "

5 Days, 12 Hours, 44 Minutes. 
 
4th Prestige level 26. I think I'm a little addicted to that game....

8days playing 3days in matchmaking 
 
Great job IW.

Haven't checked lately but probably around the 4-5 day mark.

I'm pushing 6 days but I am ready to quit.
 
I am at my wits end with some of this retarded shit they have no plans on tweaking or fixing. Marathon is broken. I use the hell out of it but its too fast - you can rush and watch people spawn right in front of your eyes and whats the point of SitRep, with Marathon you can leap over claymores. Auto-aim gets me killed every 5 minutes. I don't know if its in conjunction with the holidays and all the new kids playing, but all I know is auto-aim is fucked when you have to fight against it just because you are shooting at 2 or more enemies. 
 
Anyone think its against a dev's best interest including an in-game timer? Makes me wanna go outside

I'm at 4 Days and X Hours..level 8 2nd prestige

In total, over a week. 5 of those days were spent on multiplayer, and I'm only first prestige level 52...