in my head MicroSD = SDXC = expansion slot. should've been more precise. I re-read the posts before mine and still no talks of memory expansion...? Or am i missing something?

Edit: and for the MicroSIM, its more of a compatibility issue. I have one of those usb 3G modems with me (since where I live, the N900 doesnt get 3G). That modem will become useless if i need a microsim, although if i already get 3G, i wont need it anymore.