Clean install Mac OS X Lion on new SSD
I have it installed in my Macbook Air, and I wanna get portable distributive.
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I believe this is what you are looking for: http://osxdaily.com/2011/07/08/make-a-bootable-mac-os-x-10-7-lion-installer-from-a-usb-flash-drive/
You can also use Carbon Copy Cloner to make an exact copy of your internal hard disk, and boot from it externally.