From August 17, a free download will contain all a Mac user will need to connect to Clearwire's slowly expanding WiMAX empire. Well, there's also the matter of a $79.99 Clear 4G+ USB modem, available from the beginning of the month, but you can rationalize that purchase by noting it can also hook up to Sprint's 3G network. Once you've got those things, and you've paid your dues -- $30 per month for mobile services -- we're sure they'll finally let you in on the
