newb question

[jtoy]

Can you tell me how I can make a python program find the IP address of
the local machine?  If possible, I would like to make this not matter
what OS its on( i want it to work on windows and Unix/Linux/BSD).
Second, can you tell me how I could run this program as a dameon, again
not OS dependent, because while I know you can put a Python script in
cron,  how can you do the same with windows?
Third, how can I make Python recognize what OS its on, that wat if I
can't do the above 2 questions withouot being OS dependent, then I will
do somethin like: if OS == x then do else OS == z do
Thanks for your time.