Is there an easy way to use binary modes in GPSs with an arduino. Also what calculations need to be done to turn this into lat/long?
The data that you normally get from a GPS is in lat/long form. That is, it's circular measure relative to the Greenwich meridian. If you want rectilinear measurement, e.g. in metres relative to the Ordnance Survey grid, you'll need to make a transformation. It gets quite mathematical, quite quickly! May well be too floating-point intensive for the Arduino to do at a reasonable rate. I've done it with the ARM chip in an iPaq, a few years ago.
poke around diydrones.com . Jordi (also on this forum) has created a very stable and efficient binary parser for the em406 gps module