PSP-Maps 2.2

Royale's Maps application for the PSP; supporting Google Maps, Yahoo Maps, and Virtual Earth. PSP-Maps v2.0 introduces basic support for the PSP-290 GPS receiver.PSP-Maps is a tool that allows you to browse Google Maps, Virtual Earth and Yahoo Maps with your PSP and its WiFi connection. You can move around the map, zoom in and out, cycle through the different available views, search for an address, load/save favorites, etc.

It includes a cache system so you can browse later the maps you have previously seen, even if you don't have WiFi available.
There is also a PC version if you don't have WiFi at all, so you can build a cache on your computer and copy it to your PSP.

Technically, PSP-Maps connects directly to the servers to fetch the images, it does not use the provided APIs since there are usually in JavaScript and not convenient for a homebrew.