Then you'll want to read about Carbon Hero, a UK- and Netherlands-based startup.
The company has developed an application in Java ME that rides along in your BlackBerry, Nokia Nseries or other smartphone, uses the built-in GPS to track your travel, and presents you with your personal "carbon footprint' or carbon emissions level.
To manage copious amounts of mapping and other data, all within the device's tight memory and storage constraints, Carbon Hero uses McObject's Perst Lite open source, object-oriented Java ME embedded database system.
For its efficiency, ease of use and small footprint, Carbon Hero's CTO calls Perst Lite "just what we need."
For more information about Carbon Hero and its use of Perst Lite, see McObject's writeup at:
http://www.mcobject.com/pressroom.php?step=3&article=111
Regards,
Ted Kenney
Marketing Director
McObject