I have another coolant leak....great

[Alkasquawlik]

As some of you may know, I blew a coolant gasket on my way down to Bimmerfest and had to limp my car down to SLO where I was able to patch it up.

I just back from work today, and noticed my engine was smoking a bit. I immediately popped the hood and saw I was leaking coolant. This time it was underneath the heater valve, dripping out of some tube.

I have no idea what this is, so before I can begin to tackle it, I need to know what is wrong with the car.
I took some pictures.










It's that little top looking thing in the center of the pictures, and the coolant seems to be dripping out of the bottom of it. You can even see in the pictures that underneath it, it looks like its wet and green thanks to the leaking coolant.

Any ideas on what it is and how easy it is to fix?


TIA

[SpecM]

looks like the spot where the TB heater hoses leak onto