If you're running 2.1 already, you can't do it from a mac tothe best of my knowledge. When I wiped, 2.1 automatically downloaded and I lost root but fortunately I had wife's laptop to use. If you can somehow get back to 2.01, you can then root using a mac- basically just follow the instructions for a pc but do everything from the phone, not through ADB. That's how I did it...it wasn't difficult.