Logged In: YES 
user_id=341410

It's not a Python issue.  I can run multiple copies of
Python in the same console.  It's the
non-forking/non-threaded web server the OP is using.

bash-2.05b$ /cygdrive/c/python24/python -c \
> "import time;time.sleep(1);import
sys;sys.stdout.write('hello\r\n');\
> sys.stdout.flush();[i for i in xrange(10000000)];\
> ss.stdout.write('goodbye\r\n');sys.stdout.flush()" &
[1] 2380
bash-2.05b$ /cygdrive/c/python24/python -c "import
time;time.sleep(1);import sy
s;sys.stdout.write('hello\r\n');\
sys.stdout.flush();[i for i in xrange(10000000)];\
sys.stdout.write('goodbye\r\n');sys.stdout.flush()" &
[2] 1468
bash-2.05b$ hello
hello
goodbye
goodbye

[1]-  Done                    /cygdrive/c/python24/python -c
"import time;time.s
leep(1);import
sys;sys.stdout.write('hello\r\n');sys.stdout.flush();[i for i in
xrange(10000000)];sys.stdout.write('goodbye\r\n');sys.stdout.flush()"
[2]+  Done                    /cygdrive/c/python24/python -c
"import time;time.s
leep(1);import
sys;sys.stdout.write('hello\r\n');sys.stdout.flush();[i for i in
xrange(10000000)];sys.stdout.write('goodbye\r\n');sys.stdout.flush()"
bash-2.05b$