==SCons==

+ When giving CC and CXX on the command-line you can specify what compiler
  to use:

  scons CC=gcc-3.3 CXX=g++-3.3

SConstruct

@@ -108,6 +108,13 @@ if not env:
     print "Could not create a build environment"
     Exit()
 
+cc = B.arguments.get('CC', None)
+cxx = B.arguments.get('CXX', None)
+if cc:
+	env['CC'] = cc
+if cxx:
+	env['CXX'] = cxx
+
 if env['CC'] in ['cl', 'cl.exe'] and sys.platform=='win32':
     platform = 'win32-vc'
 elif env['CC'] in ['gcc'] and sys.platform=='win32':

tools/btools.py

@@ -37,14 +37,14 @@ def validate_arguments(args, bc):
             'WITH_BF_FTGL', 'BF_FTGL', 'BF_FTGL_INC', 'BF_FTGL_LIB',
             'WITH_BF_FFMPEG',
             'WITH_BF_PLAYER',
-            'CFLAGS', 'CCFLAGS', 'CPPFLAGS',
+            'CFLAGS', 'CCFLAGS', 'CPPFLAGS', 
             'REL_CFLAGS', 'REL_CCFLAGS',
             'C_WARN', 'CC_WARN', 'LLIBS', 'PLATFORM_LINKFLAGS',
             'BF_PROFILE_FLAGS' ]
     arg_list = ['BF_DEBUG', 'BF_QUIET', 'BF_CROSS', 'BF_UPDATE',
             'BF_INSTALLDIR', 'BF_TOOLSET', 'BF_BINNAME',
             'BF_BUILDDIR', 'BF_FANCY', 'BF_QUICK', 'BF_PROFILE', 'BF_DEBUG',
-            'BF_PRIORITYLIST', 'BF_BUILDINFO'
+            'BF_PRIORITYLIST', 'BF_BUILDINFO','CC', 'CXX'
            ]
 
     all_list = opts_list + arg_list