To compile the windows version you need a mingw32 cross compiler
toolchain (binutils, gcc, g++, etc). See this page for more pointers

  http://www.ecn.wfu.edu/~cottrell/cross-gtk/

To compile gpscorrelate for win32 you need cross-compiled versions of:
 libiconv
 gettext
 cairo
 atk
 libpng
 libxml2
 pango
 pixman
 zlib
 expat
 fontconfig
 freetype
 gettext
 glib2
 gtk2
 exiv2


Once you have all the dependencies cross-compiled, export
PKG_CONFIG_PATH to the database of your toolchain environment
(somehting like /usr/i486-mingw32/lib/pkgconfig/)

Finally run 
 # make -f Makefile.mingw32

(Makefile.mingw32 and README.mingw32 written and contributed by Julio Castilo. Thanks!)
