Micro-SD.

The software is pretty impressive, won't allow the "extra" access on the phone but even allows you to connect your PC to the Internet through your phone if you have that capability.
I'm still waiting on my 580i, backordered. Checked it out on HowardForums and found out it's a pretty kick-azz phone. Hopefully it'll be worth the wait.
BTW, none of my phones have text, email, internet, etc... capabilities. I really don't have a need for it. Make calls, take pics, play music. Alarm clock, calculator, other features are just bonus. I'm not paying extra for stuff I don't need. If I want a ring tone I rip it using Audicity on my PC, then load it to the phone via USB cable.