earth map help

hello all, hopefully i have posted in the right forum i am currently playing about with blender (newbie)
i have created a blank sphere to be a planet, i have a moving cube but when i go around the planet it falls off. is there a way to make it so it acts as a planet so as you go around its the right way up etc like it is in reality and it doesent fall off. i have got version 2.49 and 2.57 of blender.
i hope i have explained it properly.
many thanks all

You want it to orbit ? Im not sure i understand. add spear - add cube - edit cube-select all verts - move all verts ( cube in edit mode ) - below the screen there is a button ( default button is 2 circles but the icon changes ) click it, it will say “Pivot point” select individual centers - press r key r rotate