You can put some more maps on a microsd card but keep in mind that the *.img file can't be larger then 2GB on the 60Csx. In my 60Csx I have City Navigator and TOPO maps. But switching between these two is really a pain in the .... (you know). So I just bought some microsdhc cards with 4gb capacity and just keep the cards in a special little card holder in my pocket.