C.
Hi -
I did ship my milk home on several business trips when I was breastfeeding.
I got supplies from Uline ahead of time and brought them with me so that I would not have to find anything while on my business trip. (http://www.uline.com/). I bought insulated shipping boxes and cold packs (you can see them here: (http://www.uline.com/Catalog_View.asp?rfx_page=39&IND.... I bought the cold packs because when frozen solid (I used the freezer at the hotel), they will keep your milk cold for the shipment, and it was easier than dealing with dry ice.
I pumped my milk and put it in breastmilk freezer bags. I kept those in the refrigerator. Only the ice packs were frozen. I used FedEx to ship it home - priority overnight so that it'd get there in the morning. I had to go to a special FedEx location anyway becuase i was shipping a liquid and the Kinko's location wouldn't accept it. My husband told me that my milk would arrive very cold and everything worked out great.
I hope this helps!
C.