It's called a "minimap".

So, I took a break from tanking for a night and played my arcane mage.  I love this toon and love all the buffs that they have given us in this latest patch (thank you Blizzard).  But I have noticed a pattern with some tanks that, as a person who normally plays a tank, I just don't understand.  Let me paint a picture for you so you can see exactly what I'm talking about....

The group engages a boss and, due to most people not ever having been on that fight, the group wipes.  No big deal, everyone releases and starts to come back in and meet up at the boss.

Tank: ready?

Hunter: r

Mage: r

Death Knight: r

Tank charges in and......wipe.

Tank: WTF?

Hunter: What happened dude, you got one shotted.

Tank: Healers fail

Healer: I wasn't even in the room. Did you see a "r" from me? No, you didn't.

Tank: WTF NOOB!

*Tank leaves party*

Ok, now lets point out a couple of problems with this entire situation.  First off, the healer was partially at fault as he/she could have said they weren't ready.  HOWEVER, the tank did notice the "r" from everyone else and I'm assuming that he/she can count that there were only 3 "r" responses.  Which would be that 1 person was not ready, so why pull.  If you are not sure if they are or not, you can just ask, it won't hurt or burn to be nice and ask, lol.  Next, there is a simple thing in game, even addons to make it far more customizable, that makes this entire situation really a tank fault problem.  It's called a "minimap" and it sits on everyones screen displaying where all people in your group are at any given time.  If you ask "ready?" and you see that one of the dots on your minimap are not where you are, then someone is not ready.  It really is as simple as that. I have been seeing this kind of thing alot with tanks when I play dps and I just don't get it.  

Come on tanks, you are giving the rest of us a bad name. A tank is supposed to have full situational awareness of what is going on around them in order to do their job, but if you fail to watch your minimap to see if everyone is there for a pull, it is not much different then going in to a pull with a healer out of mana.  It causes undue stress and strain on the group and usually leads to wipes and people leaving the group.  And since everyone wants to have a nice smooth run, just please, join the rest of us and pay attention to eveything around you.....even your minimap.