Hey there, Mike.
I have sucessfully downloaded and unzipped files using a great free app called "ES FILE EXPLORER" from google play.It allows you to search your phone for downloaded files, and unzip them easily to a directory of your choice.
I also find this app incredibly useful when copying files over to my droid from my pc. You can move, copy, paste, and perform a few other key functions as well. I reccomend this app to anyone and to be honest I dont know how Id get by without it.