The Garmin nuvi 260 GPS shows up as 2 FAT drives (internal and flash) when connected with a standard USB-miniUSB cable.

Links:

Gentoo hardware wiki, with some general info http://gentoo-wiki.com/HARDWARE_Garmin_nuvi

How to install this site's Malaysia/Singapore maps http://www.malsingmaps.com/wiki/index.php/Quick_and_Dirty_Guide_for_the_Simple_People

Creating custom POIs wiki http://www.howtointernets.com/wiki/index.php/Creating_Custom_Points_of_Interest_for_a_Garmin_Nuvi_Handheld_GPS