Originally Posted by
kanebear
The TomTom is a bit odd in that it can't see an SD card and internal memory at once. So, you can load the US maps onto an SD card and then pop that out when you're done, or (re)load the UK/European maps AND put the US maps on an SD card and have it all at once. That's the route I took.
TomTom 3rd edition doesn't have a slot for an SD card. Internal memory only. And I think the internal memory isn't enough to manage more than one map.