I disagree with some of you with the Can't Do attitudes. I have a Garmin StreetPilot 2610. All of the map data for it, including Points-Of-Interest and routing data for all of North America fits into 1.5GB of my 2GB CF card (that is in the 2610).
About once a year, Garmin publishes a DVD with the latest version of the map data and I reload it all into my GPS. These annual updates run $75 each year. If I don't want/need the latest map data, I don't pay the $75 and I keep using what I've got.
Yes, if new roads get built, I sometimes find that the map data in my GPS doesn't match real life. But, I've never found it to be a big deal.
So, with 8 GB SD cards available that work in (at least) the 8130, I can't see any reason why somebody (Garmin? Please?) couldn't do what he's (the OP) asking for. My 8130, with map data for all of North America loaded into (I already have an 8 gig SD in it), and a BT puck to provide a position would make a pretty darn handy alternative to my StreetPilot. Especially when I'm afoot.
Verizon 8130 (on the bench, now
Verizon 9530 (replaced by VZW 4 times, then with a 9550)