Arduino + GPS + OpenStreeMap

Before I get too into the weeds and while I'm waiting for parts to come in, I need some community advice/guidance:
With the following hardware and Software:
SainSmart 3.2" TFT LCD with SD card reader for a Mega
Sparkfun GPS module
OpenStreetMap

I know this sounds like I'm trying to re-invent the wheel here, but what I want to do is use OpenStreetMap with an Arduino and GPS module to display real-time location on a map overlay. Yes, I'm re-engineering work done by Garmin and TomTom, et. al. but eventually I want to use Xbees to communicate GPS data between different modules and display all their locations on-screen. If any one has a better way to make this happen, or hacks/tricks for off-the-shelf GPS devices to accomplish the same result I would more than welcome the input!

I guess the Arduino platform is underpowered for your project. It has simply not enough memory to interpret OpenStreetMap data and render them. Even with prerendered maps it may be a quite slow experience with an Arduino displaying the map data. Theoretically it might be possible (only with prerendered maps) but the are will be limited (prerendered maps use a lot of storage space) and only on to perhaps three zoom levels.

Okay, so maybe an actual map overlay might be a bit much for a microcontroller, but here's another idea...

Suppose instead I use 3-axis electronic compass module with a GPS to output real-time lat/long along with dynamic compass heading and graphic representation of my location in relation to others around me? The picture would better describe what I'm envisioning...

Arduino_radar.png

That looks real do-able... just some simple display's

Bob

You'll need a communication module (GPRS or something similar) to transmit your location to your friends and vice-versa. But the rest seems feasible to me.