Localization project using Google Map's

I would like to do some localization project on Nokia N80 using Google Maps for school work.
I am new to mobile programming and was wondering if anyone could point out any tools or API's available to do this ( both in C++ and Java).
I did look at the other postings in this forum related to this topic but I was also wondering if it is possible to do this using the Google Maps application that is installed
on the phone locally as an interface instead of communicating with Google directly as you would from a PC using PHP for instance. I would like to possibly have a more dynamic interface than just dowloading a map of a location from google and then
ploting a single point in it. I would possibly like to draw trajectories of objects moving on a map in real time and display this dynamically.

Also I'm woundering if this is possible to be done in Java
instead of C++. Reason is that I would like to make the applicatin as system (phone) independent as possible.
However i don't know how possible it is to achieve this.

Thanks in advance,
Burim