$ cd /path/to/gdal-1.10.1

/* -------------------------------------------------------------------- */
/*      Use options process to get .my.cnf file contents.               */
/* -------------------------------------------------------------------- */
    int nPort = 0, i;
    char **papszTableNames=NULL;
    std::string oHost, oPassword, oUser, oDB;
//     char *apszArgv[2] = { (char*) "org", NULL };
//     char **papszArgv = apszArgv;
//     int  nArgc = 1;
//     const char *client_groups[] = {"client", "ogr", NULL };

    my_init(); // I hope there is no problem with calling this multiple times!
//     load_defaults( "my", client_groups, &nArgc, &papszArgv );
//
//     for( i = 0; i < nArgc; i++ )
//     {
//         if( EQUALN(papszArgv[i],"--user=",7) )
//             oUser = papszArgv[i] + 7;
//         else if( EQUALN(papszArgv[i],"--host=",7) )
//             oHost = papszArgv[i] + 7;
//         else if( EQUALN(papszArgv[i],"--password=",11) )
//             oPassword = papszArgv[i] + 11;
//         else if( EQUALN(papszArgv[i],"--port=",7) )
//             nPort = atoi(papszArgv[i] + 7);
//     }
//
//     // cleanup
//     free_defaults( papszArgv );

# make directory for build output
$ mkdir ogr_plugins

# compile shared plugin, statically linking in libmysqlclient (multi-line, single command)
$ g++ -Wall -g ogr/ogrsf_frmts/mysql/*.c*
-shared -o ogr_plugins/ogr_MySQL.dylib /usr/local/mysql/lib/libmysqlclient.a
-Iport -Igcore -Iogr -Iogr/ogrsf_frmts -Iogr/ogrsf_frmts/mysql
-I/Library/Frameworks/GDAL.framework/Headers -I/usr/local/mysql/include
-framework GDAL -lz -install_name ogr_MySQL.dylib

*/ #just closing comment for SE syntax highlighting

# copy plugin to known GDAL_DRIVER_PATH (sudo needed)
$ cd ogr_plugins
$ sudo cp -f ogr_MySQL.dylib /Library/Application Support/GDAL/1.10/PlugIns/

$ cd /path/to/gdal-1.10.1
$ otool -L ogr_plugins/ogr_MySQL.dylib
ogr_plugins/ogr_MySQL.dylib:
        ogr_MySQL.dylib (...)
        /Library/Frameworks/GDAL.framework/Versions/1.10/GDAL (...)
        /usr/lib/libz.1.dylib (...)
        /usr/lib/libstdc++.6.dylib (...)
        /usr/lib/libSystem.B.dylib (...)

$ ogrinfo --formats | grep 'MySQL'
-> "MySQL" (read/write)

from osgeo import ogr
sorted([ogr.GetDriver(drv).name for drv in range(0,ogr.GetDriverCount())])