Crap! I just realized that using fMMS on my N900 without having internet plan will cause extra charges for every MB transmitted.
Is this correct?
I didn't think of this earlier since I have the texting/multimedia, in addition to my voice plan, that allows normal MMS.

EDIT: My concern is whether or not fMMS uses internet to send the pictures, or does it send them through the MMS service of my cell provider? If it's the first, then I'll be getting charges for every kb sent. But if it's the second, then I'm not worried.