The 310 is an older analog EPIRB and won't be of much use past Feb 2009.
The original poster wanted a gps system that would let others know of their location. Such systems do exist but I don't know of any that are world wide? Perhase aksing at boating stores may get you on teh right track - think about those around the world ocean yatch people. You certainly MUST NOT use an EPIRB system - the E stands for EMERGERNCY and should only be used for such - fines here are heavy for improper use.
Regards Frank Warner
motorcycles BMW R80 G/S 1981, BMW K11LT 1993, BMW K75 G/S