How to download zip file for iPhone
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I'd like to download a zip file containing mp3s for my app. Then, I will need to unzip it into a permanent directory, which will contain the mp3s to be played on demand. This is a vocabulary app and the zip file contains the mp3 to be extracted (and played when requested). 

What's a good directory to download these to? How to do unzipping? Also, the files, or rather, the web directory they are in, is password protected, so I will need to provide the name and password.  

Does anyone have any general pointers? In particular, I'd like to know how to provide the user name / password, the best directory to download to, how to unzip the file, and how to download. Any code samples would be greatly appreciated.  