The file Mac/README in Python 2.6b3 says:

Installing in another place, for instance $HOME/Library/Frameworks if 
you have no admin privileges on your machine, has only been tested very 
lightly. This can be done by configuring with --enable-
framework=$HOME/Library/Frameworks. The other two directories, 
"/Applications/MacPython-2.6" and /usr/local/bin, will then also be 
deposited in $HOME. This is sub-optimal for the unix tools, which you 
would want in $HOME/bin, but there is no easy way to fix this right
now.


In reality, the framework is installed in the directory given on the 
command line, but the installer then wants to write the app to 
/Applications/MacPython-2.6 and crashes due to lack of write permission:

DYLD_FRAMEWORK_PATH=/shared_scratch/Python-2.6b3:  ../python.exe 
./scripts/Buil\
dApplet.py \
        --destroot "" \
        --
python=/shared_scratch/Library/Frameworks/Python.framework/Versions/2\
.6/Resources/Python.app/Contents/MacOS/Python`test -f 
"/shared_scratch/Library/\
Frameworks/Python.framework/Versions/2.6/Resources/Python.app/Contents/M
acOS/Py\
thon-32" && echo "-32"`  \
        --output "/Applications/Python 2.6/Build Applet.app" \
        ./scripts/BuildApplet.py
kCGErrorRangeCheck : Window Server communications from outside of 
session allow\
ed for root and console user only
./scripts/BuildApplet.py:34: DeprecationWarning: catching of string 
exceptions \
is deprecated
  except buildtools.BuildError, detail:
Traceback (most recent call last):
  File "./scripts/BuildApplet.py", line 149, in <module>
    main()
  File "./scripts/BuildApplet.py", line 33, in main
    buildapplet()
  File "./scripts/BuildApplet.py", line 116, in buildapplet
    progress=verbose, destroot=destroot)
  File "/Volumes/User data/Scratch/Python-2.6b3/Lib/plat-
mac/buildtools.py", li\
ne 115, in process
    copy_codefragment, raw, others, filename, destroot)
  File "/Volumes/User data/Scratch/Python-2.6b3/Lib/plat-
mac/buildtools.py", li\
ne 140, in process_common
    is_update, raw, others, filename, destroot)
  File "/Volumes/User data/Scratch/Python-2.6b3/Lib/plat-
mac/buildtools.py", li\
ne 327, in process_common_macho
    builder.build()
  File "/Volumes/User data/Scratch/Python-2.6b3/Lib/plat-
mac/bundlebuilder.py",\
 line 147, in build
    os.mkdir(builddir)
OSError: [Errno 13] Permission denied: '/Applications/Python 2.6'
make[1]: *** [install_BuildApplet] Error 1
make: *** [frameworkinstallapps] Error 2