I put the milk in the freezer and then bring it home just like that. But I take taxi home and it just takes me 10 mins. You can also buy an ice pack to keep your milk cool when travelling home, then you can just put your milk in the fridge in the office.
You can check on this link to find more information:
http://www.askdrsears.com/html/2/T026900.asp
If you pump more than once at work, you can wrap your pump in plastic wrap or put it in a ziplock bag and put it in the fridge.