There Goes the Bimmer

i was driving around Atlanta today on my way to downtown when I felt the need to turn on the air conditioner for the first time in 2 months.  Everything was going all good (so I thought) until my "CHECK" light came on, I looked up and low and behold, it said "COOLANT." 

I watched the temperature gauge start to increase a little bit so I instantly shut down the A/C, stopped the fan, turned off the radio and just tried to do what I could.  I was driving on backroads for a little bit but I reached my destination and hung out for an hour or two.  When I got out of the car though, my car was leaking coolant explosively.  It was just all over the parking spot. 

To make a long story short, I then again headed off to work, but stopped as a gas station along the way, bought some 50/50 mix (2 bottles just in case), poured one of the bottles in the reservoir, took off and a little while later, my temp gauge spiked to red, then passed red. 

DSC04543I couldn't wait any longer, and just continued to drive to work so that I wouldn't be late.  By the time I got to the parking lot, I had been running with the temp needle past the red (I mean like at the 3:00 position) an the car started making funny noises like clicking by the time I reached the employee lot.  Now, its just sitting there as I'm away for 4 days, and I plan on having it towed somewhere --> maybe the stealership because I don't know of any good mechs in the ATL area.  (Any help there anyone?) 

So, what damage could I have done driving for 20 miles with the temp gauge pinged at 3:00 and what else should I look for?  These pictures and the engine itself I could not really take a close look because of the time constraint, but to tell you the truth, I'm afraid.  It seems like it's going to cost a pretty penny.