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Wirelessly posted (iPhone 4s: Mozilla/5.0 (iPhone; CPU iPhone OS 5_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9B179 Safari/7534.48.3)

I use StuffIt does what it says on the tin
 
Do you want to extract them or create them?
Because both tools are already built into Mac OS X.
Double click on a .zip file to extract it, and select several files or folder and right-click and select Compress to make a .zip file.
 
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