It’s from XRoad and covers only a few U.S. cities,but apparently G-Map (unfortunate name,I’ll offer) is ok by Apple as it’s said to be available via the AppStore. It’s a large download (700 Mb free space needed) and apparently downloads all the data so there’s no need for a connection to do a search or get directions.
TG Daily notes that v 2.2 of the iPhone firmware will include StreetView and opens up navigation. The current firmware version is 2.1 and it seems the app above is delivered on that version,though product page does not specify.
via Electric Pig