Apparently, you can't - or at least I haven't found a way to do this either.
The closest I've come up with is when you select an address from your contact list, it will open the maps application and show that location on the map. But that's hardly an elegant alternative.
well if that is true that you cant thats pretty ******ed. ARE there any maps that where u can save location? are there google maps on n900? or anyotherway?