Someone else has pointed out verizon's 5GB "flaw", so i'll point out Sprint's: they don't ship cards "ready-for-mac-use", they don't provide a Mac OSX Connection manager, and they don't provide quality Mac tech support!
No problem, the solution is EVDOinfo.com! check out:
http://www.evdoinfo.com/content/view/1888/63/
and speaking of Guy Kawasaki... he's a customer of ours:
http://blog.guykawasaki.com/2006/08/geek_week.html
The Macintosh Way: At Work