Here is an attempt to bring Google Maps to the PSP with a simple interface. This program is not using the Google Maps API (except for address search), it is retrieving the images directly.

Changes:

added Virtual Earth and Yahoo! Maps support (thanks to boomerang for the idea)
address search menu
customizable cache size
added an option to load neighborhood to cache
switched to TTF font
fixed a bug with favorites
new buttons mapping

Other release notes:

I hope you will enjoy it!
The Virtual Earth and Yahoo Maps support was quite easy to add since the tile system is very similar to Google Maps.
The address search menu uses the Google Maps API, with a static API key in the source code. In fact I realized the API key is not “secret” since it is visible on a website source code for example. However, if it generates too much traffic it might be disabled…

You can now setup PSP-Maps to have a very big cache. And you can use the “load neighborhood” option to load the tiles around the current position in the cache, with a large radius (useful to generate a map for offline usage).

http://royale.zerezo.com/psp/